Act 311



COMMONWEALTH OF
PENNSYLVANIA
DEPARTMENT OF ENVIRONMENTAL
PROTECTION
BUREAU OF DEEP MINE
SAFETY
 
ACT 311
GAS DETECTION
COURSETable of ContentsGoalObjectivesMaterialsTime
RequiredPresentationApplicationEvaluationClass
CritiqueSection
1 - House Bill 2550, Act 311Section
2 - Introduction to Mine GasesSection
3 - Approved Flame Safety LampSection
4 - Hand Held Detecting Devices30
Foot Probe GuidlinesSection
5 - VentilationAct
311 - Final Review
 

I. GOAL:
To instruct future certified personnel in the recognition
and detection of harmful gases and in the measurement of ventilation currents
underground.
 
II.
OBJECTIVES:
1. Review of House Bill 2550, Amendment 311 of
1974.
 
2. Introduction to Mine Gases.

A. Explanation of TLV, STEL, and Specific
Gravity.

B. Converting PPM to Percentage.

C. Individual mine gases and mine
damps.
 
3. Flame Safety Lamp.

A. Function of the Flame Safety
Lamp.

B. Disassembly and reassemble of the Flame Safety
Lamp.

C. Use of the Flame Safety Lamp.
 
4. Hand Held Detecting Devices.

A. Wheatstone Bridge Theory.

B. Types of gas detecting devices.

C. Extended probe guidelines.
 
5. Ventilation.

A. State Law.

B. Air measurements and use of the
Anemometer.

C. Use of Smoke Tubes.
 
6. Practical application and evaluation.

A. Detecting Methane/Oxygen in gas
chamber.

B. Air measurements using
anemometer.

C. Flame Safety Lamp assembly.

D. Methanometer demonstration with the extended
probe.

E. Written exam - Certification
cards.
 
III.
MATERIALS:
1. Manual - Overheads - Flame Safety Lamp - Anemometer -
Gas Detecting Devices - Smoke Tubes - Probes - Fan Charts - Gas Chamber -
Various Gases.
 
IV. TIME
REQUIRED:
6.5 Hours
 
V.
PRESENTATION:
Instructor, with the aid of the manual, demonstrations,
and lecture, will present the material necessary so the students will be able
to recognize and detect harmful mine gases and understand the use of the
anemometer and the measurement of ventilation currents.
 

VI.
APPLICATION:
The students will contribute to the class through question
and answer sessions, hands on use of the flame safety lamp, demonstration of
the anemometer, probe, and methane detecting devices.


 
VII.
EVALUATION:
The students will demonstrate the ability to assemble the
flame safety lamp, detect methane with the flame safety lamp, use the
extendible probe with the methanometer, and use an anemometer to make air
readings.
 
VIII. CLASS
CRITIQUE:
Class evaluation forms to be completed by
students.
 
 
 
 
Section 1
 
Review of House Bill
2550
Amendment
311
 
Amendment 311
Session of 1974
 
AN ACT
 
Amending the act of July 17, 1961 (P.L. 659,
No. 339), entitled



"An act relating to bituminous coal mines; amending
revising. consolidating and changing the laws relating thereto; providing
for the health and safety of persons employed in and about the bituminous
coal mines of Pennsylvania and for the protection and preservation of
property connected therewith; prescribing penalties; and repealing
existing laws, " providing fro certifications and use of noncertified
persons under certain temporary conditions.


 

The General Assembly of the Common wealth of Pennsylvania
hereby enacts as follows:
Section 1. Sections 206 and 210, act of July 17,
1961 (P.L. 659, No. 339), known as the "Pennsylvania Bituminous Coal Mine
Act," are amended as read:
 
Section 206. Qualifications for Certification. --
(a) Applicants for certificates of qualification as mine foreman
[assistant mine foremen,] and mine electricians, [mine examiners,]
shall be citizens of the United States, of good moral character, and of known
temperate habits, at least twenty -three years of age, and shall have at least
five years practical experience after eighteen years of age, as miners or
mining engineers or men of general work [inside] with at least three years
experience in working sections ( a working section for the
purposes of this act shall be deemed to the area from the working face
extending back one thousand feet) in underground bituminous
coal mines: Provided, That graduates [in the coal mining course of a
recognized institution of learning] with bachelors degree in civil
engineering, electrical engineering or mining engineering, or an associates
degree in the mining engineering course of a recognized institution of
learning may , after examination, be granted certificates of qualification
by an examining board as mine foreman, [assistant mine foremen,] and
mine electricians, [mine examiners,] if possessed of an aggregate of not less
than three years practical experience as miners or men of general work or
mining engineers, [inside] in underground bituminous coal mines in
the working section. [Applicants for certificates of qualification as
first grade mine foremen, mine examiners and mine electricians, shall also
have had experience in gas mines. All applicants shall be able to read and
write the English language intelligently, and shall furnish the board with
certificates as to their character and temperate habits, which certificates
shall also show the length of service in the different mines.]
 
(a.1) Applicants for certificates of
qualification as assistant mine foremen shall be citizens of the United
States, of good moral character and of known temperate habits, and shall have
had at least four years practical experience , with at least three years
experience in working sections, after eighteen years of age, as miners or
mining or mining engineers or men of general work with at least three years
experience in working sections in underground bituminous coal mines: Provided,
that graduates with bachelors degree in civil engineering, electrical
engineering or mining engineering, or an associates degree in the mining
engineering course of a recognized institution of learning may , after
examination, be granted certificates of qualification by an examining board as
mine foreman, and mine electricians, if possessed of an aggregate of not less
than three years practical experience as miners or men of general work or
mining engineers, in underground bituminous coal mines in the working
section.
 
(a.2) Applicants for certificates of
qualification as mine examiners shall be citizens of the United States, of
good moral character and of known temperate habits, and shall have had at
least three years practical experience after eighteen years of age, as miners
or mining or mining engineers or men of general work with at least three years
experience in working sections.
 
(a.3) All applicants shall be able
to read and write the English language intelligently, and shall furnish the
board with certificates as to their character and temperate habits, and a
notarized statement from previous employers setting forth the length of
service and type of work performed in the different mines.
 
(b) Certificates of qualification as mine foremen
shall [be of two grades, namely: Certificates of first grade shall] be granted
to persons who have given to the examining board satisfactory evidence of
their ability to perform the duties of mine foremen [in gassy mines] and
have received training by persons approved by the Department in determining
the presence of explosive and noxious gases, and in the use and mechanics of
all gas detection devices, and who shall have received an average of at
least eighty per cent in the [ second grade] examination [ and at least eighty
per cent in the first grade examination. Certificates of second grade shall be
granted to persons who have given the examining board satisfactory evidence of
their ability to perform the duties of mine foremen in non gassy mines, and
who shall have received at least eighty per cent in the second grade
examination].
 
(c) Certificates of qualification as [first grade]
assistant mine foremen shall be granted to persons who have given to the
examining board satisfactory evidence of their ability to perform the duties
of assistant mine foremen [in gassy mines] and have received training by
persons approved by the Department in determining the presence of explosive
and noxious gases, and in the use and mechanics of all gas detection
devices, and who shall have received an average of at least seventy per
cent in the [ second grade] examination [ and at least seventy per cent in the
first grade examination. Certificates of qualification as second grade
assistant mine foremen shall be granted to persons who have given the
examining board satisfactory evidence of their ability to perform the duties
of assistant mine foremen in non gassy mines, and who shall have received at
least seventy per cent in the second grade examination].
 
(d) Certificates of qualification as mine examiners
shall be granted to persons who have given to the examining board satisfactory
evidence of their ability to perform the duties of mine examiners [in gassy
mines] and have received training by persons approved by the Department in
determining the presence of explosive and noxious gases, and in the use and
mechanics of all gas detection devices, and who shall have received an
average of at least seventy-five per cent in the mine examiners
examination.
 
(e) Certificates of qualification as mine
electricians [in gassy mine] shall be granted to persons who have given to the
examining board satisfactory evidence of their ability to perform the duties
of mine electricians and have received training by persons approved by the
Department in determining the presence of explosive and noxious gases, and in
the use and mechanics of all gas detection devices, and who shall have
received an average of at least seventy-five per cent in the mine electricians
examination.
 
(f) Certificates of qualification or service
heretofore granted shall have equal value with certificates of qualification
granted under this act; provided , however, those certificates heretofore
granted for second grade mine foremen or second grade assistant mine foremen
will not entitle the holders to act in gassy mine.
 
(g) All applicants who have satisfactorily passed a
written examination shall also satisfactorily pass an oral examination, [ but
the examining board shall have authority to exempt any applicant from the oral
examination for justifiable reasons] and after being certified but before
assuming their duties as mine foremen, mine electricians, assistant mine
foremen or mine examiners, shall accompany a certified mine foreman or a
certified assistant mine foreman for not less than two weeks for training
purposes in accordance with a training program submitted by the operator and
approved by the department: Provided, however, that any applicant who has been
granted a prior certificate need not undergo this training. The record of such
training shall be maintained at the mine.
 
Section 210. Unlawful to Use Noncertified
Persons.-- (a) It shall be unlawful for any operator, manager, or
superintendent, to employ as mine foreman in a bituminous coal mine, or as
assistant mine foreman in a bituminous coal mine, any person who has not
obtained the proper certificate of qualification required by this act:
Provided, That certificates of qualification heretofore granted shall have
equal value with certificates of qualification granted under this act
except as provided in section 206 (f) of the act. It shall also be
unlawful for any operator, manager, superintendent , or mine foreman, to
employ as mine examiner in a bituminous coal mine any person who has not
obtained the proper certificate of qualification under this act: Provided,
That certificates of qualification as [fire boss} mine examiner
heretofore granted shall have equal value with certificates of qualification
granted under this act: Provided, however, That in an emergency, which
shall be a condition which could not have been foreseen and which requires
immediate action, the mine foreman may [ deputize temporarily] appoint
a competent person or persons with no less than three years experience
in underground bituminous coal mines to act as assistant mine foreman or
mine examiners, for not more than one week, but this authority shall
not be exercised by the mine foremen so long as certified assistant mine
foremen or certified mine examiners are available in the mine who are
willing to accept the assignment. In other situations, if a certified person
is not available, a mine examiner may be appointed to act as assistant mine
foreman, but only until an assistant mine foreman, who is willing to accept
the assignment becomes available, for a period or periods not exceeding one
hundred twenty working production days within a twelve-month period or thirty
days after the examination, whichever is longer.
 
(b) Nothing in this article shall prevent a [first
grade] mine foreman from acting as assistant mine foreman in any mine [or a
second grade foreman from acting as assistant mine foreman in a non-gassy
mine. Nothing in this article shall prevent a first grade assistant mine
foreman from acting as a mine foreman in a gassy mine] or an assistant mine
foreman from acting as a mine examiner.
 
(c) Foremen trainees, where used, shall not
direct the working forces in matters involving directly or indirectly the
safety or employees nor make tests or examinations required to be made by
certified persons.
 
Section 2. This act shall take effect immediately
except that sub-section (c) of Section 210 shall become effective at the end
of the sixth calendar month after the month this act becomes effective, or
March 31, 1975, whichever is later.
 
Section 2
 
Introduction to Mine
Gases
 
 

Noxious: Nonpoisonous, however can dangerous if
displaces oxygen.
 
Toxic: Poisonous, either by short exposure or long
exposure.
 
Specific Gravity: The weight of a ratio of a
specific gas compared to the same ratio of air.
 
Graham's Law: The rate of diffusion, the lower the
specific gravity, the faster it will diffuse.
 
Threshold Limit Value (TLV): The amount of a gas
exposure for an 8 hour day for 5 days a week without any harmful
effects.
 
Short Term Exposure Limit (STEL): The amount of gas
exposure for only 15 minutes.
 
Parts Per Million (PPM): The most accurate
measurement of a contaminant in the atmosphere.
 
PERCENT PPM
 
1.0........................................10,000
.1...........................................1,000
.01............................................100
.001............................................10
.0001............................................1
 
AIR
 
Chemical Formula: none Specific Gravity: 1.000
 
Color: None Odor: None
 
Taste: None Origin: Atmosphere
 
Pure dry air at sea level contains the
following:
Oxygen - 20.94 %
Nitrogen - 78.09 %
Argon - 0.94%
Carbon Dioxide - 0.03%
 
OXYGEN

Chemical Formula: o2 Specific Gravity: 1.105
Color: None Odor: None
Taste: None Origin: Found naturally in
atmosphere.
Explosive Range: None Ignition Temp: None
TLV: None STEL: None
% Oxygen Needed: Not applicable. Effect on Body: Necessary
to support life.
How Detected: Flame Safety Lamp, Electronic Detectors,
Chemical Analysis.
 
Oxygen Present Effect
(percent)
21 % Breathing Easiest
19.5 % Minimum Amount of Oxygen Required by
Law.
17% Breathing Faster and Deeper.
16.25% Flame Safety Lamp Extinguishes (no methane
present)
15% Dizziness, Buzzing Noise, Rapid Pulse, Headache,
Blurred Vision.
9% May Faint or Become Unconscious.
6% Movement Convulsive, Breathing Stops, Shortly After
Heart Stops.
 
HYDROGEN
Chemical Formula: H2 Specific Gravity: 0.0695
Color: None Odor: None
Taste: None Origin: Applying water to super hot mine
fires, explosions electrolysis of battery acid.
Explosive Range: 4.1% - 74% Ignition Temp: 1030o - 1130o
F
% Oxygen Needed: 5% TLV: None
STEL: None Effect on Body:Asphxysiant Due to Displacement
of Oxygen.
How Detected: Electronic Detectors, Squeeze Tube
Detectors, Chemical Analysis.
NOTE: Hydrogen is the reason a flame safety lamp is
not permitted in a battery charging station.
 
NITROGEN
Chemical Formula: N2 Specific Gravity: 0.967
Color: None Odor: None
Taste: None Origin: Found naturally in atmosphere, small
amounts can be released from coal seam.
Explosive Range: None Ignition Temp: None
% Oxygen Needed: Not Applicable. TLV: 810,000
STEL: Not applicable Effect on Body: Asphyxiant due to
oxygen deficiency.
How Detected: Flame Safety Lamp, Chemical
Analysis.
 
CARBON
MONOXIDE
Chemical Formula: CO Specific Gravity: .967
Color: None Odor: None
Taste: None Origin:Product of Incomplete Combustion:
Fires, Explosions, Blasting, Diesel Motors.
Explosive Range: 12.5% - 74% Ignition Temp:
11000 (F)
% Oxygen Needed: Can be Explosive as Low as 6
%.
TLV: 50 PPM STEL: 400 PPM
Effect on Body: Displaces O2 in Hemoglobin of
Blood (affinity is 300 times more
than oxygen)
How Detected: Electronic Detectors, Squeeze Tube
Detectors, Chemical Analysis,
 
Percentage of Blood Saturation: Symptoms
1-10 None (every day exposure)
10-20 Tightness Across Forehead, possible
headache.
20-30 Headache, Throbbing Temples.
30-40 Severe Headache, Weakness, Dizziness, Dimness of
Vision, Nausea, Vomiting, and Collapse
40-50 Same as above but with more intensity.
50-60 Fainting, Increased Pulse and Respiration, Coma with
Intermittent Convulsions.
60-70 Coma, Convulsions, Depressed Heart Action and
Respiration, Possible Death.
70-80 Weak Pulse, Slowed Respiration, Death.
 
CARBON
DIOXIDE
Chemical Formula: CO2 Specific Gravity: 1.529
Color: None Odor: None
Taste: Distinct Acid Taste in High
Concentrations.
Origin: Product of Complete Combustion, Oxidation of
Carbon and Organic Materials, also in Exhaled Breathing Air.
Explosive Range: None Ignition Temp: None
% Oxygen Needed: Not Applicable.
TLV: 5000 ppm STEL: 15,000 PPM
Effect on Body: Will Increase Breathing Rate Because of
Body's CO2 Drive, Will Cause Asphyxiation Due to Displacement of
Oxygen.
How Detected: Flame Safety Lamp, Electronic Detectors,
Squeeze Tube Detectors, Chemical Analysis.
 
METHANE
Chemical Formula: CH4 Specific Gravity: .555
Color: None Odor: None
Taste: None Origin: Decomposition of Organic Matter in the
Presence of Water and the Absence of O2.
Explosive Range: 5% - 15% Ignition Temp: 1100o - 1380o
(F)
(dry) (humid)
% Oxygen Needed: 12% or More is Needed for CH4
to Burn or Explode.
TLV: Not Applicable STEL: Not Applicable
Effect on Body: Asphyxiation Due to Displacement of
O2.
How Detected: Flame Safety Lamp, Methanometer, Squeeze
Tube Detectors, Chemical Analysis, Riken.
 
HYDROGEN
SULFIDE
Chemical Formula: H2S Specific Gravity:
1.191
Color: None Odor: Rotten Eggs (Stink Damp)
Taste: Slight Sweet Taste Explosive Range: 4.3% -
45%
Origin: Rotting Mine Timbers, Stagnant Acid Mine Water,
Blasting of Some Sulfide Ores.
Ignition Temp: 700o F % Oxygen Needed: NONE
TLV: 10 PPM STEL: 15 PPM
Effect on Body: Will Cause Paralysis of Olfactory System
After a Few Inhaled breaths, and if not removed, will eventually cause
respiratory paralysis.
How Detected: Distinctive Odor in Minute Concentrations,
Squeeze Tube Detectors, Electronic Detectors, Chemical Analysis.
 
NITROGEN
DIOXIDE
Chemical Formula: NO2 Specific Gravity: 1.589
Color: None in Low Concentrations, Reddish Brown in High
Concentrations.
Odor: Burnt Powder Odor. Taste: None
Origin: Blasting, Diesel Engines, Electric Arc
Welding.
Explosive Range: None Ignition Temp: None
% Oxygen Needed: Not Applicable TLV: 5 PPM
STEL: 10 PPM
Effect on Body: Forms Nitric Acid When in Contact With
Body's Mucous Membranes and Respiratory System, Causing Pulmonary
Edema.
How Detected: Squeeze Tube Detectors, Chemical Analysis,
Electronic Detectors.
 
SULFUR
DIOXIDE
Chemical Formula: SO2 Specific Gravity: 2.264
Color: None Odor: Strong Sulfur Odor.
Taste: Acidic Origin: Burning of Sulfide(pyrites) Ores,
Diesel Fumes, Gob Fires.
Explosive Range: None
Ignition Temp: None % Oxygen Needed: Not
Applicable.
TLV: 5 ppm STEL: 10 ppm
Effect on Body: Creates Sulfuric Acid When Comes in
Contact With Mucous Membranes and Respiratory Tract, Causing Pulmonary
Edema.
How Detected: Electronic Detectors, Squeeze Tube
Detectors, Chemical Analysis.
 
ACETYLENE
Chemical Formula: C2H2 Specific
Gravity: 0.9107
Color: None Odor: Garlic Aroma
Taste: None Origin: When Methane is Heated or Burned in a
Low Oxygen Atmosphere.
Explosive Range: 2.4% - 83% Ignition Temp: 581o
F
% Oxygen Needed: None TLV: None
STEL: None Effect on Body: Asphyxsiant Due to the
Displacement of Oxygen.
How Detected: Smell, Squeeze Tube Detectors, Chemical
Analysis.
 
MINE DAMPS
Damp is a derivative of the German word damph,
which means gas or air, from the immigrant German coal miners working in the
anthracite field.
black damp: carbon dioxide and nitrogen in an oxygen
deficient atmosphere which will cause suffocation.
white damp: carbon monoxide
stink damp: hydrogen sulfide
fire damp: methane
after damp: the after products of an explosion of fire:
carbon monoxide, carbon dioxide, water vapor, nitrogen, oxygen, hydrocarbons,
and hydrogen.
 
Section 3
 
Approved Flame Safety
Lamp
 
TERMS AND
DEFINITIONS
 

BONNET - THE METAL CASING WITH OPENINGS FOR
VENTILATION. IT
PROTECTS THE GAUZES FROM DAMAGE AND FROM THE IMPACT OF
HIGH-VELOCITY AIR.
 
CAP - THE BLUE HALO OF IGNITED METHANE WHICH SHOWS
ABOVE CAP FLAME OF A SAFETY LAMP WHEN IN AIR CONTAINING SMALL QUANTITIES OF
METHANE. ALSO CALLED GAS CAP.
 
CAP-FLAME - A PALE BLUE SPOT OF FLAME ON THE TOP OF
THE WICK OF A SAFETY LAMP. IT IS ADJUSTED BY LOWERING THE WICK AND IS USED FOR
THE DETECTION AND MEASUREMENT OF METHANE GAS.
 
EXPANSION - METAL RING DESIGNED TO ALLOW FOR
EXPANSION OF THE RING GLOBE.
 
FONT - THE BASE OF THE FLAME SAFETY LAMP THAT
CONTAINS THE ASSEMBLY FUEL STORAGE AREA, THE IGNITER ASSEMBLY, WICK,
FLAME ADJUSTMENT, AND THE LOWER GAUZE RING.
 
GASKET - A FLAT ASBESTOS WASHER USED FOR MAKING
AIRTIGHT JOINTS ABOVE AND BELOW THE GLOBE.
 
GAUZE - HE WIRE MESH USED TO PREVENT THE PASSAGE OF
FLAME FROM THE LAMP TO THE EXTERNAL ATMOSPHERE.
 
GLOBE - THE PORTION OF THE LAMP THAT CONTAINS THE
ASBESTOS ASSEMBLY GASKETS, THE GLOBE, AND THE GASKET RING.
 
WICK - A THIN BUNDLE OF THREADS DESIGNED TO ABSORB
FUEL TO BE BURNED WITH A SMALL STEADY FLAME.
 
TRAVELING - A LUMINOUS YELLOW FLAME USED FOR THE
PURPOSE OF FLAME DETECTING AND MEASURING METHANE.
 
OXYGEN - WHEN THE OXYGEN CONTENT OF THE MINE AIR IS
REDUCED
DEFICIENCY - BELOW THE ALLOWABLE LIMIT OF THE LAW
(19.5 VOLUME PER
CENTUM).
 
PERMISSIBLE FLAME SAFETY
LAMPS
 

HISTORY AND THEORY
 
The flame safety lamp operates on a principle credited to
Sir Humphrey Davy more than a century ago. Davy found that when a metal
screen or gauze was placed over a flame, it would not pass through the gauze.
The wire gauze safely confined the flame by rapidly dissipating the heat, thus
reducing the temperature of the flame below ignition level.
 
Davy's lamp was designed primarily for its safe light;
however, it soon became the standard device for detecting the presence of
methane and the most practical means of detecting the deficiency of oxygen in
mine atmospheres. When the lamp is intact, properly cleaned and assembled, the
gauzes give the only direct openings to the outside. They permit enough air
movement through the interior of the lamp to provide a sufficient amount of
oxygen for the wick flame to burn yet prevent the passage of flame from the
lamp to the external atmosphere surrounding it. This occurs even though the
gas-air mixture explodes within the lamp.
 
The U.S. Bureau of Mines has tested flame safety lamps
under adverse conditions that may exist in the mines and has designated as
permissible two types of lamps--the Koehler and the Wolf.
These lamps are safe to use under all conditions, provided they are
properly assembled of permissible parts and used by a qualified person. These
lamps are the only permissible lamps known to be in use in the United
States.
 
The Koehler flame safety lamp, the
most common type, is composed 10 basic parts which can be divided into three
major groups:
 
1. The fount assembly or base of the lamp
contains--

a. The fuel storage area for a
12-hour supply of fuel.

b. The igniter assembly, which is used in
lighting the lamps.

c. The wick assembly and
wick, which is used to draw up a steady supply of fuel from
the reservoir for combustion.

d. The wick adjustment knob, which is used
to adjust the height of the flame.

e. The lower gauze ring, which allows air
to enter the lamp.
 
2. The globe assembly contains--

a. Asbestos gaskets, one above and
one below the globe, to provide adequate tight joints at each end of
the globe.

b. The globe, an approved glass for
observing the flame.

c. The gasket or globe ring,
which retains the upper asbestos gasket.
 
3. The bonnet assembly contains--

a. The hood and bonnet for
protection of the upper gauzes from mechanical injury and protection from
high velocity air currents entering the lamp.

b. The outer gauze, which safely
confines the flame by its rapid cooling effect, preventing propagation of
the flame from within the lamp to a gassy atmosphere surrounding
it.

c. The inner gauze, which serves the same
purpose as the outer gauze. The use of two gauzes insures a much greater
safety factor.

d. The expansion ring, which permits
expansion of the globe when heated without creating excessive end
pressure.

e. The baffle ring, which protects the
lower gauze and insures a more stable flame by preventing direct access of
air through the lower gauze.

f. A magnetic lock that prevents opening
the lamp underground.

g. Standards to protect the globe against
breakage from external blows.
 
 
CARE OF FLAME SAFETY
LAMPS
 

Sequence of Disassembly
 
Disassembly of the flame safety lamp should be in the
following order:
 
1. Place a magnet on the two lock pins of the magnetic
locking device and unscrew the bonnet from the fount.

a. Turn the lock pins in a clockwise direction until a
click is heard. The click indicates that the lock is free and the magnetic
lock open.

b. Unscrew the pins in a counterclockwise direction,
continuing to hold the magnet on the two lock pins until the bonnet and
fount are separated.

c. The expansion ring will remain between the
standards.
 
2. Remove the outer and inner gauzes.
 
3. Remove the gasket ring, globe, and lower gauze ring and
gaskets.
 
The lamp is now broken down into its basic components and
is ready for cleaning, filling, and inspection.
 
Cleaning, Filling, and
Inspection
 
When all removable parts of the lamp assemblies are
detached, the procedure is as follows:
 
1. All deposits should be removed from the igniter file
wheel. The igniter should then be tested and adjusted to provide adequate
sparking.
 
2. The wick raising device should be inspected and charred
material cleaned from the wick.
 
3. To fill the lamp, remove the filler plug and fill the
fount with a suitable fuel at the designated filling station located in the
lamp house. Fill the fount sufficiently to completely saturate the cotton
packing and wick. The fluid should not be allowed to run over. The excess
fluid should be poured from the fount after each filling. Replace the filling
plug, tighten adequately, and properly seat it against the filling-plug
gasket.
 
NOTE: The use of suitable fuels is
most important. Because of excessive gumming, motor gasoline is not suitable
as a flame-lamp fuel. Suitable fuels are uncolored, straight-run
gasoline, having a medium distillation range of 900 to
3300F.
 
4. To clean the inner, outer, and lower gauzes, brush with
a soft brass bristle brush or blow with low compressed air. The gauzes should
be examined for broken wires and enlarged or obstructed holes. A new gauze
should have the coating burned off before being used. Gauzes should be made of
either iron or brass screen having a mesh of
28 or 30
(784 or 900 holes per square
inch).
 
5. Clean the globe (lamp glass) thoroughly. It should be
examined for defects, especially cracks and chipped edges.
 
6. Carefully inspect the asbestos gaskets for possible
defects and breaks. Defective or doubtful gaskets should be replaced since
they will not form an airtight joint above and below the globe.
 
7. Clean the bonnet assembly of soot or dust and carefully
examine for defects. Deformation of the bonnet usually interferes with normal
ventilation and burning of the lamp and may seriously lower its safety
factor.
 
Sequence of Assembly
 
To permit proper assembly of the lamp from the bottom up,
observing that each part is in its proper place up to the time of locking the
lamp, and for the purpose or thoroughly examining the condition of each part
during assembly, assemble as follows:
 
1. Begin with the fount assembly which has been properly
filled with a suitable fuel, thoroughly cleaned, and all parts examined for
permissibility and to insure they are in good working conditions.

 
2. If assembling a Wolf lamp, properly position the
baffle ring on the fount.
 
3. Insert an asbestos gasket in the lower gauze
ring and properly set it in place on the fount.
 
4. Place the globe (lamp glass) in its proper
position.

a. Koehler lamp--The inscription, "Pyrex,
made in the U.S.A.," or the word "Top" should be in a
reading position.

b. Wolf lamp--The inscription, "Wolf, made
in the U.S.A.," or the word "Top" should be in a
reading position.

c. Inscriptions must be placed in a reading position to
insure proper positioning of the etched line
graduations.
 
5. Insert an asbestos gasket in the gasket ring (globe
ring) and place it over the globe, if assembling a Koehler lamp. When
assembling the Wolf lamp, first assemble the inner gauze, the outer gauze, and
gauze ring. Then, insert an asbestos gasket in the gauze ring.
 
6. Place the inner and outer gauze over the
globe.
 
7. Insert the expansion ring between the standards of the
bonnet assembly.
 
8. Place bonnet assembly, with expansion ring in place,
over the gauzes.
 
9. Screw bonnet assembly to fount threads in a clockwise
direction until tight; see that the magnetic lock operates and that the lamp
is locked. A test for proper tightness is to grasp the globe with the thumb
and first two fingers and turn. The globe should turn with resistance for
correct tightness. Turning easily or not at all is incorrect.
 
Preliminary Test
 
After the safety lamp is assembled and before it is taken
underground, it should be tested in a lamp-testing box containing an explosive
mixture of gas and air.
 
1. The unlighted lamp is placed in the box.
 
2. The igniter of the lamp is then operated to fire the
mixture which has entered the lamp.
 
3. If the lamp is defective or improperly assembled, the
explosion inside the lamp will ignite the gas-air mixture surrounding the lamp
causing the rupture of a paper diaphragm at the top of the box.
 
 
Possible Errors In
Assembly
 
Some of the errors likely to occur in assembling the lamp
are as follows:
 
1. Omitting one or both gaskets or using broken
gaskets.
2. Omitting one of the gauzes.
3. Failing to adequately tighten the fuel filler
plug.
4. Failure to inset expansion ring.
5. Failure to adequately tighten the bonnet to the fount
to make a tight fit between the globe glass and the gaskets.
6. Tightening the fuel fount too much, compressing the
expansion ring and destroying its usefulness.
7. Omitting the baffle ring (when assembling the Wolf
lamp) which prevents air from blowing directly into the lamp through the lower
gauze.
8. Using a distorted shield or bonnet.
9. Placing a defective gauze in a lamp.
10. Not examining each part to see that it is clean and in
good condition.
 
Using the flame safety
lamp
Preliminary checks
 
In most cases the flame safety lamps will be maintained by
a competent and qualified lamp man who is assigned to that job. However, there
is a procedure which the person qualified to use the lamp should follow prior
to taking the lamp into the mine:
 
1. Check to see if the lamp is locked.
 
2. Visually inspect the lamp for dents and
dirt.
 
3. Check to see if the outer gauze is in place by looking
down between the hood and the top of the deflector.
 
4. Check to see if the inner gauze is in place by looking
up through the globe.
 
5. Check the upper asbestos gasket on the globe to insure
that it is in the ring, properly seated, and not defective.
 
6. Check the globe for cracks, chips, and proper
seating.
 
7. Check the lower gauze ring to see that it is in place
and that the asbestos gasket is in proper position and not
defective.
 
8. Observe the filler plug to insure that it is properly
tightened below the surface of the fount.
 
9. Check the tightness of the globe. You should be able to
turn the globe with resistance, using your thumb and two fingers.
 
10. Check the which and the wick feed adjustment by
turning the wire adjustment knob on the bottom of the fount.
 
11. Check the igniter for proper operation and snap lock
it in the down position.
 
Lighting and Flame
Adjustment
 
Being satisfied the lamp is permissible, it should be lit
and the flame adjusted in an atmosphere free of methane as follows:
 
1. Extend the wick.
2. Elevate the igniting device.
3. Rotate the igniter until a spark is
produced.
4. Adjust the wick for the desired height of
flame.
 
Testing for Methane
 
Handling the lamp in the process of testing for methane is
of great importance and should be done as follows:
1. It is held firmly, in either hand, by the fuel fount
and always in an upright position.
2. Since methane is lighter than air it will be found in
the higher locations of the mine or working place.
3. The lamp must be raised slowly. It is very unwise to
thrust a lighted safety lamp in a mine atmosphere known to be potentially
explosive. By raising the lamp slowly the atmosphere can be thoroughly
explored.
4. Immediately, when the behavior of the flame indicates
that gas is present, the lamp should be withdrawn slowly. Hasty withdrawal
will tend to drive the flame through the gauzes.
5. In the event that a safety lamp is thrust
unintentionally into an explosive mixture, which may be indicated by the lamp
filling with flame or the wick flame going out, it should be withdrawn slowly
and taken to fresh air for relighting.
 
Detection of Methane
 
The detection of methane on the flame of a safety lamp
consists of observing the lengthening of the flame due to the burning of the
gas in contact with the flame. Two different methods are employed.
 
1. Observation of the draw or change in the height of the
traveling flame with the aid of the lined globe.
2. Lowering the wick until the flame is nonluminous and
then observing the gas cap.
 
Traveling flame method
 
1. The height of the flame should first be adjusted in
fresh air to establish a base height. The highest practical heights are as
follows: 1 inch, or to the middle ring of the globe for the Koehler
lamps; and 7/8 inch for the Wolf lamps.
 
2. When in the area to be tested, carefully handle the
lamp as previously prescribed. Raise it slowly, continuously observing the
yellow luminous flame. If methane is present, by knowing the base height of
the flame you will readily see the change in its rise.
a. Accurate measurements come only with experience, but
when using this method, one can approximate that for every 1/32 to 1/16
of an inch rise of the flame, 0.5 percent volume of methane is
present.
 
"Cap" flame method
 
The "cap" flame method is better suited for
accuracy and is more positive as an indicator. It will show the presence of
gas when there is no opportunity to establish the normal setting of the 1-inch
high flame in known fresh air.
 
1. Lower the wick until only a small blue cap flame
remains at its top.
 
2. Tests for methane in the same manner as with the
traveling flame method by slowly raising the lamp into the testing zone while
constantly observing the cap flame. Complete darkness is required for this
method since the pale blue flame elongation is quite difficult to see. The
rise of the gas cap is the measure of methane content in the air. Skill in
accurately measuring the methane content in the air. Skill in accurately
measuring the methane content is obtained only through experience and
practice. Concentrations as low as 0.5 per cent per volume are readable
when using the cap flame method.
 
Detecting oxygen-deficient
atmospheres
 
Oxygen is necessary for the support of life and
combustion. Men breathe most easily and work best when the air contains
about 21 percent oxygen, which is the amount usually present in normal
atmospheres; yet, they can live and work, though not as well, when there is
less oxygen. Men breathing air that has 15 percent oxygen
usually become dizzy, notice a buzzing in the ears, have a rapid heartbeat,
and often suffer from headache. When the air contains only about 7
percent oxygen, life is greatly endangered.
 
1. The flame safety lamp will not burn in a
methane-free atmosphere having an oxygen content below 16.25
percent; however, it will burn in atmospheres of lower
oxygen content if methane is present. The lamp flame will be
extinguished when the oxygen content falls below 13
percent, regardless of the percentage of methane present.

 
No one should try to enter or remain in an atmosphere in
which a flame safety lamp will not burn unless he wears a self-contained
breathing apparatus.
 
2. In a methane-free atmosphere, reduction of the oxygen
content of the mine air below the normal 20.95 percent (19.5 Percent is the
lower percentage permitted by law) materially affects both the temperature
and the illuminating power of the flame.
 
3. The first evidence of oxygen deficiency below 16.25
percent is an initial increase in flame height in its search for oxygen,
followed by a decrease, and the immediate extinguishment.
 
4. Tests show that when methane is present in a mine
atmosphere which is deficient in oxygen, the flame height alone is not a
reliable indicator of either the percentage of methane content or oxygen
deficiency. However, observation of both the height and color of the flame
shows reliably the presence of more than 1.5 percent of methane or less
than 16 percent of oxygen or combinations of these conditions.
 
Limitations of the flame safety
lamp
 
The flame safety lamp has been a very reliable piece of
equipment for more than a century. It has made possible the development and
operation of mines that otherwise never could have been worked and has
contributed much to miners' safety. However, the lamp does have definite
limitations:
 
1. It is doubtful whether the average observer can
measure less than 1 percent of methane with the ordinary
lamp.
 
2. When enough methane is present, the percentage of gas
may be roughly estimated by the height of the "cap," but these estimates are
likely to differ considerably from the true value.
 
3. Men charged with the responsibility of detecting
methane should be thoroughly experienced and competent in the use and care of
lamps. They should be checked for good eyesight and color
perception.
 
4. IN THE STATE OF PENNSYLVANIA THE FLAME SAFETY
LAMP IS STILL THE PRIMARY DETECTING DEVICE FOR CHECKING METHANE AND OXYGEN
DEFICIENCY ACCORDING TO THE MINING LAWS OF
PENNSYLVANIA.
 
5. No device can replace the practice of safety and
caution which must be a part of the miners' everyday life.
 
VENTILATION OF THE FLAME
SAFETY LAMP
85% to
90%
10% to 15%
2/3 Intake - 1/3
Exhaust
 
 
Section 4
 
Hand Held Detecting
devices
 


THE WHEATSTONE
BRIDGE
 
Resistor R1 is the reference element. It is a
fixed resistor, but its value will vary slightly with atmospheric
temperature. It is mounted near the sensing element to compensate for
atmospheric effects upon RX.
 
Resistor R3 has a fixed
resistance.
 
Resistor RX is the sensing element. Its
resistance will vary according to some variable factor which will be
measured.
 
Resistor R2 is a potentiometer, which has
variable resistance. By the use of R2, we adjust the balance of
the bridge until the meter reads zero. (This is electrical zero).
 
When the bridge is balanced, there is no difference in
potential between points A and C, thus no current through the meter, and it
will read zero.
 
At this time, the voltage drop across RX is
equal to that of R2, and the voltage drop across R1 is
equal to that of R3.
HAND HELD
DETECTORS
 

CSE 102 METHANOMETER (single
gas)
Gases detected: Methane(Pre-Set)
Range of Detection: 0% to 9.9%
Display: L.E.D.
Principle of Operation: Catalytic Diffusion
Sampling Method: Manual Operated Internal Pump
 
MSA METHANE SPOTTER (single
gas)
Gases detected: Methane(Pre-Set)
Range of Detection: 0% to 9.9%
Display: Needle & gage
Principle of Operation: Catalytic Diffusion
Sampling Method: Manually Operated Internal
Pump
 
INDUSTRIAL SCIENTIFIC CD210 (single
gas)
Gases Detected: Methane(Pre-Set)
Range of Detection: 0% to 9.9%
Display: L.E.D.
Principle of Operation: Catalytic Diffusion
Sampling Method: Manually Operated Internal
Pump
 
INDUSTRIAL SCIENTIFIC MDU420 (single
gas)
Gases Detected: Methane(Pre-Set)
Range of Detection: 0% to 100%
Display: L.C.D.
Principle of Operation: Non-Dispersive Infrared
Absorption(NDIR)
Sampling Method: Internal Constant Flow Pump
 
INDUSTRIAL SCIENTIFIC MX240/250 (two
gas)
Gases Detected: Methane & Oxygen(Pre-Set)
Range of Detection: 0% to 9.9% Methane
0% to 30% Oxygen
Display: L.C.D.
Principle of Operation: Catalytic Diffusion,
Electrochemical Sensor
Sampling Method: Internal Constant Flow Pump
 
INDUSTRIAL SCIENTIFIC CMX 270 (three
gas)
Gases Detected: Methane/Oxygen/Carbon
Monoxide(Pre-Set)
Range of Detection: 0% to 9.9% Methane
0% to 30% Oxygen
0 ppm to 999 ppm Carbon Monoxide
Display: L.C.D.
Principle of Operation: Catalytic Diffusion,
Electrochemical Sensor
Sampling Method: Internal Constant Flow Pump
 
CSE EXPLORER (three gas)
Gases Detected: Methane/Oxygen/Carbon Monoxide
Hydrogen Sulfide(Interchangeable)
Range of Detection: 0% to 5%-Methane
0% to 25%-Oxygen
N/A-Carbon Monoxide/Hydrogen Sulfide
Display: L.E.D.
Principle of Operation: Catalytic Diffusion,
Electrochemical Sensor
Sampling Method: Internal Constant Flow Pump
 
MSA FIVESTAR PASSPORT (four
gas)
Gases Detected: Methane /Oxygen/Carbon Monoxide/Hydrogen
Sulfide
Sulfur Dioxide/Nitrogen Dioxide/Nitric Oxide
Range of Detection: 0% to 5%-Methane
0% to 30%-Oxygen
N/A-Carbon Monoxide/Hydrogen Sulfide/Sulfur
Dioxide
Nitrogen Dioxide/Nitric Oxide
Display: L.C.D.
Principle of Operation: Catalytic Diffusion,
Electrochemical Sensor
Sampling Method: Internal Constant Flow Pump
 
INDUSTRIAL SCIENTIFIC CO 262 (single
gas)
Gases Detected: Carbon Monoxide(Pre-Set)
Range of Detection: 0 ppm to 999 ppm
Display: L.C.D
Principle of Operation: Electrochemical Sensor
Sampling Method: Internal Constant Flow Pump
 
DRAGER MULTI WARN (five
gas)
Gases Detected: Methane/Oxygen/Carbon Monoxide/ Nitrogen
Dioxide
Hydrogen Sulfide/Nitric Oxide/Carbon
Dioxide(Interchangeable)
Range of Detection: 0% to 100%-Methane
0% to 25%-Oxygen
0 ppm to 2000 ppm-Carbon Monoxide
0 ppm to 100 ppm-Hydrogen Sulfide
0 ppm to 20 ppm-Sulfur Dioxide
0 ppm to 20 ppm-Nitrogen Dioxide
0 ppm to 100 ppm-Nitric Oxide
0% to 25%-Carbon Dioxide
Display: L.C.D
Principle of Operation: Electrochemical Sensor, Catalytic
Diffusion, Infrared Sensor
 
INDUSTRIAL SCIENTIFIC TMX412 (four
gas)
Gases Detected: Methane/Oxygen/Hydrogen Sulfide/ Carbon
Monoxide
Nitrogen Dioxide/Sulfur
Dioxide(Interchangeable)
Range of Detection: 0% to 5%-Methane
0% to 30%-Oxygen
0 ppm to 999 ppm-Carbon Monoxide
0 ppm to 999 ppm-Hydrogen Sulfide
0 ppm to 99.9 ppm-Sulfur Dioxide
0 ppm to 99.9 ppm-Nitrogen Dioxide
Display: L.C.D.
Principle of Operation: Catalytic Diffusion,
Electrochemical Sensor
Sampling Method: Internal Constant Flow Pump
 
DRAGER MULTIGAS DETECTOR (single
gas)
Gases Detected: Available Sampling Tubes from
Manufacturer
Range of Detection: Determined by Sampling Tube
Display: Increments on Tube
Principle of Operation: Atmospheric reaction to Chemical
in Preset Tubes
Sampling Method: Hand Operated Bellows Pump
 
INDUSTRIAL SCIENTIFIC STX 70 (single
gas)
Gases Detected: Oxygen/Carbon Monoxide/Hydrogen
Sulfide/Nitrogen Dioxide
Nitric Oxide/Sulfur Dioxide
Range of Detection: 0% to 30%-Oxygen
0 ppm to 999 ppm-Carbon Monoxide
0 ppm to 999 ppm-Hydrogen Sulfide
0 ppm to 999 ppm-Nitric Oxide
0 ppm to 99.9 ppm-Nitrogen Dioxide
0 ppm to 99.9 ppm-Sulfur Dioxide
Display: L.C.D.
Principle of Operation: Electrochemical Sensor
Sampling Method: Internal Constant Flow
Pump
 
 
30
FOOT PROBE GUIDELINES
 

For making CH4 tests greater than 20
feet and less than 30 feet from the last permanent support.
1. Must be a digital read methane
detector.
2. Can only be used with an
A.T.R.S.
3. Plan must be submitted to
the District Mine Inspector.
4. An intermediate support to stabilize the
extended probe must be
used.
5. Constructed of aluminum, fiberglass, or
non-sparking material.
6. Test shall be made not less than
12 inches from the roof, face and ribs.
7. Methanometer shall be used for one
(1) shift only.
8. All persons shall
be instructed on the use of the probe-based
system.


 
 
 
Section 5
 
Ventilation
PENNSYLVANIA MINING LAW
-VENTILATION
 

1. The operator or superintendent of every mine shall
provide and maintain ample means of ventilation to furnish a constant. and
adequate supply of fresh air. Page 60, Section
242(a).
2. Quantity shall be sufficient to dilute and render
harmless and carry away all gases. Page 60, Section
242(a).
3. The last open crosscut shall be ventilated by an air
current of at least 6000 cubic feet per minute. Page 61 Section
242(b).
4. Not more than 70 persons shall be permitted to work on
one continuous air split. Page 61, Section 242(b).
5. Distance driven to establish ventilation connections
between rooms or entries shall not exceed 200 linear feet. Page 62
Section 243(a).
6. Crosscuts between intake and return air courses shall
be closed by permanent stoppings, except one, nearest the face. Page 62,
Section 243b
7. All stoppings between intake and return airways shall
be built of solid incombustible materials. Temporary stoppings may be used in
the crosscut nearest the face. Page 63 Section
243(e).
8. Stoppings shall be reasonably airtight. Page 63,
Section 243(f).
9. Ventilation shall be so arranged by means of airlocks,
overcasts or undercasts that passage of trips or persons will not interrupt-
the air current. Page 63 Section 244(a)
10. It is unlawful to knowingly leave a door or
check-curtain open. Page 63, Section 244(b).
11. Doors shall be self-closing. Page 63, Section
244(c).
12. Line brattice shall be used from the last open
crosscut of an entry or room to provide adequate ventilation for the workman
and to remove gas and explosive fumes. Page 64, Section
245(a).
13. The space between the rib and brattice shall be large
enough to permit a free flow of air to remove gas and dust. Page 64,
Sect. 245(b).
14. Brattice cloth shall be made of approved
flame-resistant material. Page 64, Section 245(c).
15. All areas underground shall be ventilated by air
containing not less than 19.5% oxygen, not more Than 0.5% carbon dioxide, and
no quantities of other gases. Page 61, Section
242(b).
 
 
MEASUREMENT OF AIR
VELOCITY
 

The most common instrument used to measure the velocity of
air in a mine is called an anemometer. It consists of a wheel so constructed
that, when held in a current of air, the air flowing against the vanes of the
wheel causes it to rotate. The wheel revolutions are indicated on a dial face
with several registering dials and hands. The large hand, which is used with
the large outside dial, registers a velocity of 100 ' feet in the interval of
time which the reading requires every time it makes one complete revolution:
divisions of this large dial scale will indicate a velocity as low as one-foot
per time interval. Other smaller dials on the gauge face indicate hundreds of
feet and thousands of feet velocity. Anemometers usually have a small lever
extending out from the frame near the handle by means of which the dial gears
may be engaged or disengaged from the wheel shaft as it rotates. This is of
value when timing the velocity readings., There are variations in the design
of anemometers and in the number of registering dials used, but this
description probably covers the majority of anemometers used in
mines.
 
There are a number of instruments utilized in a mine to
measure velocity of air- These instruments are based on certain principles and
therefore only suitable in a particular velocity range. Some of the most
commonly used instruments and their range are listed below.
 
Instrument Velocity Range(fpm)

 
Smoke tube 20 -120
Anemometer 150 - 2000 (also 2000 - 10,000)
Velometer 30 - 3000
Kata Thermometer 100 -1500
Pitot tube 750 -10,000
 
A velocity reading must take into consideration the time
spent. If an anemometer is held in an air current for five minutes-and the
dials register a velocity of 2,450 feet, the correct velocity reading would be
obtained as follows,
 

Dial readings / time in
minutes = Velocity in feet per minute
2,450/5 = 490 feet per minute

 

In taking a velocity measurement in an airway, it is best
practice to select a point where the area will represent the average
cross-section for the airway. If weekly readings are to be taken in this
airway, it is good practice to also mark the point where previous readings
have been taken so as to have a constant area of cross-section for comparative
quantity readings. Also, since an air current does not have the same velocity
near the sides of an airway as in the middle, it is advisable to move the
anemometer during the reading so as to cover as many as 9 or 12 points well
distributed throughout the airway's cross-section and thus obtain an average
velocity. The person taking the reading should hold the anemometer at arms
length so as to minimize the interference of the body to the air current. A
watch must be used to time the reading. As the watch minute hand passes over
the 60-second mark, the lever engaging the dial gears with the wheel shaft
should be moved so that the anemometer begins to register the air's velocity.
When the time limit decided for the reading has been reached, the lever is
again moved to stop the dial hands. The difference between the initial and
final readings divided by the time in minutes gives the velocity in feet per
minute.
 

There is always a possibility that an anemometer gives
slightly inaccurate readings. Sometimes the instrument manufacturer will give
a constant by witch the velocity readings must be multiplied to give accurate
results (this is to overcome the inertia of the instrument). There is a slight
error in true velocity created by having the observerłs body near the
instrument and this probably overcomes the slight inaccuracy of the
instrument. Should an accident occur to the wheel of the anemometer, such as a
slight extra twist to the vanes, it may cause so much inaccuracy that serious
in ventilation calculations may result. If damage is suspected, the anemometer
should be returned to the manufacturer for a check on ft
accuracy.
 

Air velocity does not remain constant over the entire
cross section of an opening. Therefore, it is very important that proper air
velocity measurement techniques be adopted in order to obtain a velocity that
gives a quantity closest to the real quantity flowing through the opening. A
single (or one point) measurement technique involves mounting an air velocity
measuring Instrument at the center (approximately) of the opening and taking a
few readings and then averaging them. This normally gives a close approximate
of the, maximum velocity in the airway. Multiple measurement techniques can be
either fixed point traversing type or continuous traversing type. In fixed
point traversing, the airway is divided into a number of imaginary equal areas
and the instrument is placed at the center of each of the imaginary cross
section. The average velocity is obtained by adding all t he velocities and
them dividing them by the number of imaginary areas. In continuous traversing
technique, the velocity measuring instrument is traversed slowly, evenly and
at a uniform speed in the entire cross section of the airway. This technique
gives an average velocity.
 
 
CORRECTING ANEMOMETER
READINGS
 

The indicated velocity (dial reading) does not indicate
true air velocity. Therefore, a correction table is provided with each
instrument.
 
An example is shown below. Each anemometer has a unique
correction table and cannot be used with any other anemometer.
 

 
Taking Smoke Tube
Readings

 
 
 
 
 
 
 
 
 

Note: To do this calculation, you first have to convert
the smoke tube reading into feet per minute.
Letłs say that 25 feet is the measured distance and
it averages 23 seconds fro the smoke cloud to reach the downwind point.
You need to find the decimal equivalent of 23 seconds to find what fraction of
a minute is:
 
23 seconds = .38 minute
60 seconds
 
So you would have:
 
25 feet of travel
.38 minute
 
This equals 65.7 ft/min.
 
 
ACT 311 FINAL
REVIEW
 

1. The heavier the gas is, the faster it will
diffuse.

True False
 

2. Convert 2.8% into
ppm._____________________
 

3. The legal definition of deficiency
is:


A. 19%


B. 17%


C. 19.5%


D. Less than 19.5%
 

4. An explosion cannot occur unless there is 5% methane
present.

True False
 

5. A person exposed to NO2 or SO2
can be fatal even if there are brought immediately to fresh
air.

True False
 

6. The flame safety lamp is used to:


A. Measure oxygen content in the atmosphere by observing
the reaction of


the flame.


B. Measure oxygen and methane content in the atmosphere
by judging the


heat released by the
lamp.


C. Test for oxygen and methane in the atmosphere by
observing the reaction of the flame in the
lamp.


D. None of the above
 

7. What two gases is the flame safety lamp most often used
to detect?

_________________&__________________

 

8. What is purpose of the
gauzes?______________________________________
 

9. With no methane present, the flame safety lamp will be
extinguished at:


A. 16.25%


B. 13.0%


C. 19.5%


D. 11.5%
 

10. When is the flame safety lamp not to be
permissible?


A. In the hands of an unqualified
person


B. Improperly assembled


C. Improperly cleaned and
maintained


D. All of the above
 

11. What occurs when the wheatstone bridge is
balanced?


A. Display will indicate a presence of
methane


B. Display will read
zero


C. Display will indicate 1.0%
methane


D. A difference of potential has
occurred
 

12. Detectors using catalytic diffusion can be used in all
atmospheres.

True False
 

13. Electrochemical sensors do not need oxygen to react
properly.

True False
 

14. What type of sensing device will accurately work
regardless of the oxygen

present?


A. Electrochemical


B. Infrared sensor


C. Catalytic diffusion


D. A & B
 

15. All hand held detectors can be used with the 30 ft.
probe.

True False
 

16. The air quantity requirement in the last open crosscut
shall be____________.
 

17. The body of air which is moved through a mine is
called the

___________________
___________________.
 

18. The __________________of an air current is its speed
or rate of travel.
 

19. The most common instrument used to measure the
velocity of air in a mine is

called
a(n)___________________________.
 

20. Permanent stoppings must be reasonably airtight and
built of______________________ materials.