Bascom_turner GAS-EXPLORER OM-0517 User manual

BASCOM-TURNER
INSTRUMENTS
GAS-EXPLORERDETECTORS
OPERATION MANUAL
NATURAL GAS, CARBON MONOXIDE, OXYGEN,
HYDROGEN SULFIDE
Part Number OM-0517

Publication Date: May 1, 2017
LIMITED WARRANTY
Bascom-Turner Instruments warrants Gas-Explorer Detectors to be free from defects
in materials and workmanship for one year following the date of shipment. This
limited warranty applies to the original purchaser of the Detector and is not
transferable except by Bascom-Turner's authorized Distributors.
The instruments described in this manual are produced with standard commercial
parts, any of which may fail under some circumstances. Although the probability of
such failure is low, it is not zero. Accordingly, all personnel using such instruments
must be trained to recognize instrument malfunctions and to have such instruments
repaired promptly. Bascom-Turner offers no warranty that failures will not occur –
only that when they occur, they will be promptly cured with the following procedure:
During the limited warranty period, we will repair or replace, at our option, any
defective products or parts at no additional charge. A return merchandise
authorization (RMA) number must be obtained prior to returning a detector to
Bascom-Turner. A detector returned to Bascom-Turner with probe and water-block
filter, shipping prepaid, will be repaired, calibrated and returned second day air.
Warranty repairs do not include pump cleaning, filter replacement and calibration.
All replaced parts and products become the property of Bascom-Turner Instruments.
This limited warranty does NOT extend to any Detectors which have been damaged as
a result of accident, abuse, modification, misuse, such as failure to follow the operating
instructions provided by Bascom-Turner Instruments, or other contingencies beyond
our control. No other warranty is expressed or implied. Bascom-Turner is not liable
for consequential damages.
WARNING
Personnel who operate, calibrate, or repair this instrument must
first read and fully understand this manual in its entirety.
Intrinsically safe Class I, Div 1, Groups C & D, T4
For use in Groups C and D atmospheres (Methane, Propane)
These products have not been tested for intrinsic safety in oxygen
enriched atmospheres.
Change batteries, service, and use the USB interface only in
areas known to have non-hazardous atmospheres.

TABLE OF CONTENTS
FEATURES
SPECIFICATIONS
PART 1. OPERATION
1. The Gas-Explorer Detectors ...................................................................................……
1
2. Essential Operating Practice ...................................................................................……
2
3. Operational Description..........................................................................................……
4
4. Instrument Checks ..................................................................................................……
7
5. Interference from Other Gases, Liquids or RFI......................................................……
8
6. Change of Batteries.................................................................................................……
9
7. Probes......................................................................................................................……
10
8. Routine Maintenance..............................................................................................……
11
PART 2. SETUP, CALIBRATION AND ALARM LEVEL SELECTION
1. Setup Parameters ……………………………………………………………………..
13
2. Further Setup Parameters........................................................................................……
13
3. Calibration………...……………………………………………………………………
14
PART 3. THE USB INTERFACE
1. Downloads……………. ………………………………………………………………..
...…………………………………………………………………….
16
2. Reports……...………………………...………………………………………………...
18
3. Administration…………………………………………………………………………
19
PART 4. MAINTENANCE
1. Sensor and Pump Installation..................................................................................……
20
ACCESSORIES AND SPARE PARTS

SPECIFICATIONS
Gases Detected
Natural Gas (Methane)
Carbon Monoxide (CO) [Optional]
Hydrogen Sulfide [Optional]
Oxygen (O2) [Optional]
Sensors
Dual Catalytic Combustion (CH4)
Thermal Conductivity (CH4)
Electrochemical (CO, H2S O2)
Ranges
GAS
0 to 10,000 ppm CH4by volume
0 to 100% CH4by volume
PPM CO
0 to 2000 ppm carbon monoxide
% O2
0 to 40% by volume
PPM H2S
0 to 100ppm by volume
Data Storage
24 calibrations
And
Reports
Exposure and Bar-Hole Measurements,
Calibration History, Sensor Sensitivity,
Operational Periods by User and Unit ID,
Office Reports
Accuracy CH4:
2% of reading 20ppm
(0C to 40C)
0.1% to 5 vol %
2.0% from 5% to 100 vol %
CO:
5% of reading 10 ppm
H2S:
5% of reading 1ppm
O2:
0.2% vol %
Resolution
GAS
20 ppm from 0 to 10,000 ppm
CO
H2S
0.05 vol % from 0 to 5 vol %
1.0 vol % from 5 to 100 vol %
1 ppm
1ppm
O2
0.1 vol %
Warm-Up Time
60 seconds
Response Time: CH4:
H2S/CO:
O2:
0.7 seconds (Track)
2.0 seconds (Monitor)
45 seconds
60 seconds
Operating Temperature
-20oC to 40oC (0oF to 105oF)
Storage Temperature
-40oC to 60oC (-40oF to 140oF)
Humidity
Power Supply
0 to 95% RH (non-condensing)
Two C-size Alkaline or
Two C-size Rechargeable NiMH
Continuous Operating
Time per Battery Set
10 hours typical (25oC)
Weight
24 oz. (680 g)

FEATURES
The Gas-Explorerportable methane, and combined methane, carbon monoxide, and
oxygen detectors are intrinsically safe, microprocessor based instruments designed to test
ambient air and flue gas over a wide temperature range.
These detectors have many features for easy and reliable operation:
Absolute Compliance (Optional)
The instrument automatically calls for and requires calibration at the end of a pre-
determined interval.
Automatic Data Storage and Reports
Automatic storage of time and mode-stamped readings. Automatic storage of the last
24 calibrations. Automatic generation of reports.
Automatic Calibration
Calibration is performed automatically using Bascom-Turner's calibration gas.
One-Gas Calibration (Optional)
Calibration of the thermal conductivity sensor (vs methane) is automatically carried
out with the One-Gas routine. Alternatively, the sensor can be calibrated with System
Gas.
Measurements Over the Full Range of Gas
The instruments detect methane over the full range of methane concentrations up to
100% GAS. Peak and current readings are displayed simultaneously.
Track Gas
A sensitive, calibrated scale with 20ppm resolution and quick response makes it easy
to find gas leaks.
Bar Holing
Peak and sustained bar-hole readings are automatically displayed after gas is pumped
for a precise, fixed time.
Purge
Measures the concentration of natural gas with resolution of 0.1% by volume as
sensed by the thermal conductivity sensor.
Automatic Sampling
An intrinsically safe pump automatically samples ambient air, flue gas, or bar hole
gas.
Automatic Self-Tests
Automatic checks of battery, sensors, and pump. Tests for blockage and for tight
connection of probe to instrument.
Audible and Visual Alarms
Audible and visual alarms individually set. Continuous monitoring of natural gas,
and (optionally) CO and O2.
Easy-to-Use
Simple operation without complicated or confusing displays. A short “help” manual
is stored onboard.

PART 1. OPERATION
1. THE GAS-EXPLORER DETECTORS
This manual describes the operation of the family of Gas-Explorer detectors for natural gas,
carbon monoxide and oxygen.
Model EGI -201 - Detects natural gas and displays it as PPM, % LEL or % GAS
Model EGI -211 - Detects natural gas and displays it as PPM and % GAS
Model EGC-301 - Detects natural gas and carbon monoxide and displays it as
and -311 PPM and % LEL (301) or % GAS (311) and PPM CO (parts per
million of CO)
Model EGO-321 - Detects natural gas and oxygen and displays gas as PPM, % LEL
or % GAS and % Oxygen.
Model EGO-322 - Detects natural gas and oxygen and displays PPM or %GAS and
%Oxygen.
Model EGA-411 - Detects natural gas, CO, and oxygen and displays PPM, or %
and -412 LEL (411) or % GAS (412), PPM CO and % Oxygen
Model EGA-611 - Detects natural gas, CO, H2S and oxygen and displays PPM
and -612 or % GAS, PPM CO, PPM H2S, and % Oxygen.
All models display gas in PPM in the Track Gas mode.
All models may be used to test ambient air and bar hole to locate natural gas leaking from pipes
and other conduits. All models which detect carbon monoxide (CO) may be used to test for CO
in ambient air, flue gas, and gases given off by appliances.
A detector alerts the user acoustically and visually, by "flashing" the symbol(s), for the
detected gas(es) whose concentration exceeds preset limits. Visual alarms are displayed in-
between readings. For example, the display will flash "CO", approximately every two seconds,
in-between normal Monitor mode displays. If the concentration of natural gas also rises above
its alarm limit, the display will flash “GAS”, then a normal Monitor mode display, then "CO",
and so on. Simultaneously, the sound alarm will be on.
Visual alarm symbols are “GAS” for natural gas, "CO" for carbon monoxide, HS for H2S,
"Low Oxygen" for low oxygen, and "High Oxygen" for high oxygen.
Factory set alarm limits are 1.0% methane, 35 ppm CO, 9ppm H2S, and 19.5% for
low and 23.0% for high oxygen.
No alarms are given in the Bar Hole mode.
OPTIONS
All units may have (optionally) Blue Tooth (Option BT) and/or GPS (Option GPS). The former
may be used for transmitting stored calibrations, while the latter assigns coordinates to all
measurements (gas readings) obtained by an instrument. GPS coordinates are automatically
stored together with corresponding readings of all sensors on-board.
1.
WARNING: Each detector responds to the gases for which it was designed. Other toxic
or dangerous gases may not be detected.

2. ESSENTIAL OPERATING PRACTICE
Gas-Explorer detectors are easy to use. A detector is turned on by pressing the left button;
its operation is controlled by three “Soft”buttons whose function is shown on the display. The
middle button toggles “Mute” on and off in the Track Gas mode (see later). Double-clicking the
middle button turns the backlight continuously ON, or OFF depending on its previous state.
Once the appropriate display is selected, operation is automatic. However, a few general rules
must be followed to insure reliability.
Pump. Gas-Explorer detectors have a built-in pump and depend on this pump for their
operation. If the pump is not functioning normally, the instrument will not function properly. It
is therefore essential to check the pump each time the instrument is turned on.
Pump Test: Connect the probe you plan to use and turn the instrument on. After the
display shows “Block Intake”, block the probe tip with your finger to show "Pump OK".
If "Pump OK" does not appear, tighten all connections and repeat the test. If a block
condition is still not observed, remove the probe and block directly the inlet to the instrument. If
"Pump OK" still does not appear, return the instrument for repair.
A pump test can be carried out as above at any time during normal operation. If there is
any indication that the pump is not operating normally, return the instrument for repair.
Filters. Dust and water-block filters protect the sensors and the pump from dust and
accidental intake of liquid water. Just as a car would not be operated without air and fuel filters,
do not operate a detector without a filter on the probe. Operation without this filter will
eventually degrade the natural gas sensor and the pump. It also voids the limited warranty.
Filters are available from Bascom-Turner in packages of five, Part No. WF-505 for all models
except WF-705 for EGA-611/612.
Zero Check. All sensors drift to some extent over time. Sensor drift is automatically
corrected by zeroing if the drift is within 0.1% vol. GAS (and 10ppm CO if the unit is equipped
with a CO sensor). If the drift is outside this limit, “NO GO” is displayed and the user is asked
to autozero the unit in “clean” outdoor air. The user can override this limit and re-zero the
instrument unless the zero has drifted over 1.0% vol. GAS, in which case the instrument should
be checked by a trained professional (the sensor may need replacement). It is important that the
zero adjustment be done in clean air, for example, outdoors. If the sampled gas is not clean, a
systematic error may be introduced in subsequent measurements.
WARNING: On a call, turn the instrument on outdoors, not indoors.
Test and Calibration. Gas-Explorer detectors must be checked and calibrated
periodically with gas of known composition. The catalytic combustion, carbon monoxide, and
hydrogen sulfide sensors depend on catalysts which may loose activity or get poisoned during
use. When this happens, there will be diminished response.
The necessary frequency of calibration depends on actual use and on the concentration of
catalyst poisons in the sampled gas. This concentration is, or course, not generally known.
A detector can be tested with "bump" gas. Such tests verify that the gas sensor(s) are in
operating condition. To verify and adjust, if necessary, their sensitivity they must be calibrated.
A detector can be automatically calibrated in approximately one minute using Bascom-
Turner's calibration gas (2.5% CH4and 100 ppm CO in air). Given the ease and speed of
automatic calibration, it pays to calibrate as frequently as possible, and certainly, no less than
monthly. 2.

Accuracy. A properly operating and calibrated detector will respond with the specified
accuracy. If combustible gases other than the gas used for calibration are likely or suspected, the
instrument cannot be relied upon to give a proper indication of their concentration and hence of
how close to their combustible limits they may be. For example, the detector responds quite
differently to gasoline, to methane, and to propane. Accordingly, readings of % LEL (or its
equivalent in percent gas) refer only to the calibration gas and can be relied upon only in this
respect in assessing an atmosphere sampled by the detector. Furthermore, concentrations
displayed by the detector refer to a local sample at the tip of the instrument probe. Low gas
concentrations at one spot do not necessarily mean that the gas concentration is low throughout a
wider area.
WARNING: Each detector responds to the gases for which it was designed. Other toxic
or dangerous gases may not be detected.
Safety. These instruments measure the concentration of natural gas in air and give, more
generally, an indication of the presence of other combustible gases. When used by trained
personnel, they constitute one element for assessing the safety, or lack thereof, of a particular
atmosphere. However, they must not be relied upon by themselves for judging safety; all
other significant factors must be taken into account. The measured concentration refers only
to the immediate vicinity of the probe –concentrations in a wider area may be significantly
different. A trained technician should consider possible interferences, physical or chemical, and
be aware that calibrated values are only valid in air. If other gases, including inert gases such as
carbon dioxide are present, the measurements may not be reliable. Finally, although there are
built-in safeguards, a specific instrument may malfunction. It is therefore imperative that other
indicators, including, for example, odorant levels, must be taken into account.
WARNING: Catalytic combustion sensors do not respond in inert or reducing
atmospheres. They should not be used for detecting combustible dusts or
mists.
3.

3. OPERATIONAL DESCRIPTION
To conserve the batteries, turn the instrument OFF when not in use.
The instrument is controlled by three push button switches whose function changes with
each particular display. A label for each key is shown on the display.
To turn the instrument on, press the left switch. A series of screens is automatically
displayed preparatory to entering the first operational mode, viz. “Monitor” (see Section below).
Along the way, a number of specialized screens can be used to access specialized functions.
The first screen shows the Model Number and the serial number. The second screen
displays gases detected by the particular instrument and provides access to the USB interface
(see Part 3). The next screen shows the date and time. To edit the date or time, press the right
“Edit” button. The first digit of the display will begin flashing and can be edited by pressing the
right “Update” button. Pressing the left “Next” button advances the flashing digit to the next
position which may be edited (or not) by pressing the right button, and so on. The same screen
provides access to a short manual by pressing the “Help” button.
Following the Edit/Help screen, the pump is tested (“Block Pump” screen). If no block is
detected in 40 seconds, “Check Probe” is displayed, followed by “Remove Probe and Block
Intake” and finally “Repair Pump” followed by an automatic turning off of power.
The next display shows a “Calibrate by [a date thirty days from the date of the last
calibration]” and an opportunity to calibrate (see Part 2, Calibration). If calibration is not
required, the instrument proceeds to enter the operational mode “Monitor” (see below).
The period of thirty days between calibrations is a maximum. The instrument may be
calibrated as often as possible, ideally every day. In any case, if poisoning of the natural gas
sensor or some other problem is suspected, the instrument should be promptly checked by
calibration with CAL Gas (see Part 2, Calibration).
Backlight. Pressing any button backlights the display for 20 seconds. To backlight any
display permanently, press the middle button twice (if in Track Gas mode, this sequence leaves
the instrument in its original state –mute or not mute). The only exception to this procedure is
during bar holing (middle button initiates sampling). Pressing the middle “Go” button in the Bar
Hole Mode automatically backlights the display long enough (60 seconds) to read the results.
Turning the Instrument Off. The instrument can be turned off from a number of (but
not all) displays. Such places are obvious when a particular button is marked “Off.” In all such
cases the screen accessed by pressing “Off” requires a second operation (“Yes”) to actually turn
the instrument off. This sequence guards against accidental turning off.
When a direct “Off” button is not available, you may follow the procedures suggested
below:
1. At the USB access display, press the left “USB” button and then after the new
screen, the right “Off” button.
2. During warm-up of the Track Gas mode, press the left “BH” button, then “Go”,
and then “Stop” (as soon as it appears) and then “Off.”
4.

Operational Modes. The instrument operates in four distinct modes, “Monitor”, “Track
Gas”, “Bar Hole” and “Purge”.
Monitor: The detector shows the concentration of natural gas (methane) in air in steps
of 0.05% GAS (1% LEL) up to 5% GAS (100% LEL) and then in steps of 1% GAS up to 100%
GAS. The concentrations of CO, H2S (HS), and O2are also shown if the unit is equipped with
the corresponding sensors (see below).
The peak reading for GAS is retained and displayed along with the current readings until
another mode of operation (Track Gas or Bar Hole) is chosen, or a new zero is obtained, or the
unit is turned off.
Models EGI-201, EGC-301, EGO-321, EGA-411, and EGA-611 display concentrations
in increments of 1% LEL up to 100% LEL and then in increments of 1% vol. from 5% to 100%
GAS. All other models display % vol. gas in increments of 0.05% up to 5% and then in
increments of 1% to 100% GAS.
Track Gas: Connect an appropriate probe (see Section 7) and select "TRACK GAS".
The display shows "TRACK GAS" for a few seconds. After warm-up, the display shows the
concentration of gas in air in parts per million by volume (ppm). Advance a probe along the pipe
or other conduit suspected of having a gas leak. The beeper will sound if the ambient
concentration of gas rises above 20ppm. Since methane is lighter than air, track a conduit from
above whenever possible. Sometimes it is desirable to silence the beeper during a leak survey.
To silence the beeper, press the middle switch. “Mute” will appear on the display and the beeper
will be silent. If the gas concentration goes over 10,000 ppm, (1% Gas) the unit automatically
enters the Monitor Mode.
As in the Monitor Mode, the peak reading for Gas is retrained and displayed until another
mode of operation is chosen, or a new zero is obtained, or the unit is turned off.
Bar Holing: The detector may be used to measure gas levels in sampling holes used for
locating underground natural gas resulting from seepage or leaks in a conduit. Gas
concentrations in a bar hole near a significant leak will exceed several percent. Therefore an
alarm for gas is likely, but since it is not relevant to the ambient atmospheres above ground it
will not sound. During bar-holing, the alarms for all gases are automatically turned OFF.
To bar hole, select an appropriate probe (see Section 7) and set the front panel to Bar
Hole (BH). The instrument will automatically clear any residual gas and check for clean air. The
pump is then turned off and the instrument is ready for bar holing. After inserting the probe into
the bar hole, press “GO” (the middle switch). The pump is turned on and the instrument samples
gas for a fixed time (factory set time is 15 seconds). Readings during sampling are shown on
the display. At the end of the fixed time, the instrument turns off the pump and displays the peak
and sustained readings. Both values are in % GAS.
If in the course of bar holing, water is encountered, press the left “Stop” button to stop
the pump. A water-stopper (Fig. 2 in Section 8) will prevent water from entering the instrument.
WARNING: If a check is to be made for trace amounts of gas, for example around the
foundation of a structure, the Monitor or Track Gas –not the Bar Hole –
mode should be used.
Purge: The purge mode measures the concentration of natural gas in nitrogen with a
resolution of 0.1% by volume from 0.0% to 100.0% as sensed by the thermal conductivity
sensor. Purging air-filled lines into service requires lowering the oxygen content to less than
9.7% (or natural gas concentration over 70%). 5.

To Detect Carbon Monoxide
Carbon Monoxide in Ambient Air
Connect an appropriate probe with a water-block filter and select the Monitor mode.
After warm-up, the display shows the concentration of CO in parts per million (ppm). If the air
is clean (contains no carbon monoxide), the display should read zero. If it does not, use the right
button (“Zero/Off”) to get a new zero in clean air.
Carbon Monoxide in Flue Gas
Connect the flue gas probe, with an attached flue gas filter, to the water-block filter on
the hose and select the Monitor mode. After warm-up, insert the probe into the flue and read the
concentration of CO in parts per million. A flue gas check of CO should take one minute or two.
For every minute of flue gas sampling allow the detector a minute of room air sampling to dry
the filters.
CAUTION: The filter provided with the flue probe must be used to avoid interference by
nitrogen oxides present in combusted gas. A filter is good for about three
months of ordinary use. It should be replaced or refilled when about 90% of
its purple material has changed color to brown, or when it gets clogged or
flooded (see "Accessories and Spare Parts", Flue Gas Filter, Part No. FF-005
and Purple Beads and Spare Retaining Disks, Part No. PR-050).
Note: The standard flue gas probe and filter are suitable for spot checks lasting a
minute or two. For measurements of CO in flue gas over longer periods use an
Extended Duty Flue Gas Probe and Filter (Part No. FP-012).
WARNING: Do not touch the flue probe immediately after a measurement. Wait
until it cools. Running the instrument in air helps cool the probe.
"Air-Free" CO Flue Measurements
The EGA-411/412 and 611/612 detectors can display measurements of CO on an "air-
free" basis if this feature is selected (see Part 2). When this selection is made, the measured CO
concentration is referred to air-free flue gas according to:
"Air-Free" PPM CO =
20.9
20.9 measured % O2(measured ppm CO) 
The instrument displays CO concentrations on an air-free basis using the above relation.
The CO reading on the display is labeled by ppm AFCO, i.e. air-free CO. This calculation is
used up to 16.0% Oxygen. Beyond this, measured CO concentrations are displayed without
conversion, i.e., the "air-free" formula is not used.
6.

4. INSTRUMENT CHECKS
Automatic Sensor Check
If a gas sensor fails (opens up), the display shows “Replace Methane Sensor”.
Automatic Pump Check
If the intake is blocked, the display shows "Flow Blocked" and the detector beeps until
the problem is cleared. During the power on sequence, if a blocked flow is not detected within
40 seconds (from manually blocking the intake to the pump), the detector displays “No Block
Check Probe” then “Remove Probe and Block Intake”, and finally “Repair Pump”.
Check for Tight Connections
To check for tight connections, block the probe inlet to observe "Flow Blocked" on the
display. If "Flow Blocked" fails to appear, there may be a leak.
WARNING: The instrument will not operate when first turned on if it fails to block when the
air intake is blocked. Subsequently, however, connections can only be checked by
blocking the probe inlet and observing “Flow Blocked” on the display. If “Flow
Blocked” fails to appear, the probe and/or inlet must be checked for leaks.
Automatic Zero
The zero is adjusted automatically whenever “zero” is chosen in a display.
CAUTION: Zero adjustment must be carried out in clean air to avoid systematic errors.
7.

5. INTERFERENCE FROM OTHER GASES, LIQUIDS, OR RFI
The methane detectors use two sensors:
i) A catalytic combustion filament calibrated with methane. It is used up to about
the lower flammable limit (5.0% by volume) of methane.
ii) A thermal conductivity sensor calibrated with methane. It is used from the lower
flammable limit (5.0 vol %) to 100 vol % of methane.
Models EGC-301 and EGC-311 use the sensors listed above and:
iii) A three-electrode, electrochemical cell for carbon monoxide.
Models EGO-321 and EGO-322 (methane and oxygen detectors) use the methane sensors
listed above and:
iv) A two-electrode, electrochemical cell for oxygen.
Models EGA-411/412 use all four sensors.
Models EGA-611/612 use the four sensors listed above and an electro chemical H2S
sensor.
Gases, or liquids with appreciable vapor pressure, which may interfere with the detection
of methane include substances which combust on the catalytic combustion filament (examples
are ethane, propane, ethylene, propylene, octane, and the like) and substances which differ in
thermal conductivity from air (examples are hydrogen, helium, carbon dioxide, other
hydrocarbons).
Gases or vapors which may interfere with carbon monoxide detection include substances
which can be electrochemically oxidized or reduced on the working electrode of the
electrochemical sensor. Examples are hydrogen, hydrogen sulfide, oxides of nitrogen, alcohols,
and unsaturated hydrocarbons.
Many of the substances that interfere with CO are removed by the flue gas filter (Part No.
FF-005). This filter can be used for both flue gas measurements and for ambient air
measurements of CO whenever the ambient concentration of other oxidizable substances is
significant. This filter should not be used in ambient air with EGA-611/612.
Radio Frequency Interference
The Gas-Explorer detectors have an interior coating on their cases to suppress radio
frequency interference (RFI).
8.
WARNING: The methane and CO sensors use catalysts which may be poisoned by air
contaminants. These sensors should not be exposed to atmospheres that contain
silicones, halogens and halides, such as chlorides, and volatile compounds
containing lead or antimony. If exposure to atmospheres that adversely affect the
sensors is suspected, the detector should be recalibrated promptly.

6. CHANGE OF BATTERIES
Gas-Explorer detectors may be powered by two (2) alkaline (non-rechargeable) C-size
batteries (1.5V, Type AM-3) or by two rechargeable batteries sold by Bascom-Turner. The
batteries are good for at least eight, and typically twelve, hours of continuous operation. When
the batteries are drained to about one hour of remaining continuous use, the unit alarms and the
display flashes "Low Batteries" between readings. If battery life is over, the unit displays "Low
Batteries" and powers down, and the batteries must be changed to make the instrument
operational.
WARNING: The batteries must be changed in an atmosphere known to be non-
hazardous.
To change batteries:
1. Turn instrument OFF.
2. Remove spent batteries.
a) Unscrew the battery cap and slide out two C-cells.
b) Discard two alkaline C-cells.
3. Insert two, fresh C-size alkaline batteries.
4. Replace the battery cap and give it one quarter turn (battery cap bar vertical).
Note that the batteries are inserted with the positive terminal first.
If the instrument does not operate after battery replacement, there is a high probability
that a battery has been inserted with the wrong polarity. Re-insert the batteries taking extra care
to insert each battery correctly.
Note: Always replace a set of batteries with a new set. When operating in cold weather (below
-10oC) use a fresh set of batteries, if possible.
9.
WARNING: Do not attempt to charge alkaline (non-rechargeable) batteries because
they may leak or vent.
WARNING: Use only alkaline batteries or rechargeable batteries sold by Bascom-
Turner in a Gas-Explorer.
WARNING: To reduce the risk of a battery venting, do not mix old batteries with new
batteries, or mix batteries from different manufacturers.
WARNING: Do not attempt to service the instrument in a hazardous atmosphere.

7. PROBES
Metal Gooseneck Probe
The metal gooseneck probe (Part No. GP-514) is a 14 inch long flexible probe which
connects to the dust and water-block filter and has a quick connect fitting.
Standard Probe
The standard probe (Part No. SP-306), a rigid tube, connects to the dust and water-block
filter. If extra length is desired, an extension (7", SP-308) is screwed finger-tight onto the end of
the probe. A rubber gas collector (Part No. RT-107) is useful for finding leaks under windy
conditions.
CAUTION: Do not use this probe for flue gas measurements. The plastic probe may
become soft, deform, or decompose.
Flue Gas Probe
The flue gas probe (Part No. FP-110) is a telescoping metal probe screwed finger-tight
into the flue gas filter. The other end of the filter attaches to the dust and water-block filter. This
probe, together with its filter, may also be used for CO measurements in ambient air.
CAUTION: Never attach the flue gas filter cartridge directly to the sample hose - always use
a dust and water-block filter.
WARNING: Hold the probe without touching the metal while it is in the flue and
immediately afterwards. Running the instrument in air after a
measurement will help cool the probe quickly and dry the filters.
Bar Hole Probes
There are four optional probes suitable for bar holing:
Bar Hole/Ceiling Probe (Part No. BP-034) 34" long, clear, one hole at end.
Bar Hole Probe (Part No. BP-134) 34" long, clear, side holes.
Bar Hole Probe (Part No. BP-236) 36" long, fiberglass, side holes
Bar Hole Probe (Part No. BP-536) 36" long, steel, side holes.
The bar hole/ceiling probe has a single inlet on the end and comes with a rubber gas
collector (Part No. RT-030) useful for finding leaks in overhead pipes. The stainless steel probe
has an electrically insulated handle. Bar hole probes are designed to be attached to the water
block filter on the hose. A convenient way to release water from a bar hole probe is with a
water-stopper (Part No. WS-001) described in Section 8.
WARNING: Hold the steel bar hole probe only by the insulated handle to avoid
electrical shock from buried power lines.
10.

8. ROUTINE MAINTENANCE
Dust and Water-block Filter
A filter, housed in a knurled nut, removes particles of dust and dirt and blocks water.
Do not insert objects into the water block filter as they may puncture the filter. The filter needs
to be replaced monthly or sooner if it turns brown. Replacement dust and water-block filters are
available as Part No. WF-505 (package of 5 filters). Models EGA-611/612 use WF-705 filters
only.
TheWF-505 Filter
CAUTION: Do not use a Gas-Explorer without a three-way or dust and water-block filter.
Do not use a three-way or dust and water-block filter with a puncture.
Inlet Dust Filter (IF-705)
Removal of the intake connector (used to attach the sampling hose) of the detector
exposes a metal filter pressfit onto the intake. These filters are not a substitute for dust and
water-block filters as they will not block water or remove very fine dust and dirt. If this filter
gets blocked, it may be cleaned with compressed air or replaced.
Water-stopper (WS-001)
The water-stopper (Figure 2) provides a quick way to
continue bar holing if water is encountered in a bar-hole. The water-
stopper is inserted between the dust and water-block filter and the bar
hole probe. A float inside the water-stopper is connected to a
plunger which blocks flow whenever the float is lifted by water.
Water is released and the plunger returned to its normal position by
depressing a release push-button.
Water-stopper
11.

Dust-Stopper (DS-001)
The dust-stopper is a filter with a large surface area on which dust can collect without
slowing the sampling rate of the Gas-Explorer. The filter element is easily cleaned or replaced
by removing the threaded cap and either blowing off the filter element or pulling it off and
replacing. Replacement dust filter cartridges are available as Part No. DF-105. The dust-stopper
should be used between the dust and water-block filter and the probe or water-stopper.
Flue Gas Filter
This filter is designed to be screwed finger-tight between the telescoping metal probe and
the dust and water-block filter. It must be used for CO measurements in flue gas and may also
be used for CO measurements in ambient air. The beads in the filter cartridge should be replaced
when about 90% of the material has changed color from purple to brown or when it becomes
blocked by soot or water. Filter beads for refilling approximately 50 cartridges are available as
Part No. PR-050. Replacement flue gas filters are available as Part No. FF-005 (package of 5
filters).
To refill the filter cartridge, remove threaded top and pour out spent filter material.
Retrieve the plastic retainer disk from the spent filter material. Fill cartridge with fresh filter
material to bottom of threads and place the plastic retainer disk flat on top of the filter material.
Screw in top until finger tight and check seal with block tests.
CAUTION: Do not remove or puncture the white filter in the bottom of the filter
cartridge. If this filter becomes damaged, discard the filter cartridge.
Heavy Hydrocarbon Filter
A heavy hydrocarbon filter, filled with activated carbon, is designed to be used with the
standard probe or the bar hole probe on a one-time-only basis. Activated carbon adsorbs
gasoline and other heavy hydrocarbons (for example, propane or butane) which interfere with
methane detection. In order to keep the filter material from adsorbing hydrocarbons prior to use,
the filter is fitted with plastic endcaps which must be removed just before use. The filter should
be either discarded after use or refilled with activated carbon and recapped with the plastic
endcaps. This filter is designed to be screwed finger-tight between the probe and the dust and
water-block filter. Activated carbon for refilling approximately 50 cartridges is available as Part
No. HR-050. The refill procedure is the same as described for the flue gas filter. Heavy
hydrocarbon filters are available as Part No. HF-005 (package of 5 filters).
The heavy hydrocarbon filter can also remove some alcohols and unsaturated
hydrocarbons which can interfere with CO readings. The filter should be discarded or refilled
after each use.
12.

PART 2. SETUP, CALIBRATION AND ALARM LEVEL SELECTION
1. SETUP PARAMETERS
To change setup parameters, power on the Gas-Explorer and while it displays “Bascom-
Turner Gas-Explorer” press the right button once. A menu will be displayed with a pointer:
Alarm Limits 
Bar Hole Time
Air Free CO
Power Off
The “Yes” button selects the parameter while the “No” button advances the pointer.
Once a parameter is selected the current setting can be changed by the “Edit” button. If
editing is selected, the screen flashes the parameter which can be incremented with the “Update”
button. Press the “Next” button to either advance or to leave the Edit screen and display the
edited parameter.
Alarm Limits. Alarm levels which may be saved or edited are:
%LEL Alarm Limit: 1 to 20% Factory Setting: 20%
%GAS Alarm Limit: 0.1 to 1% Factory Setting: 1%
PPM CO Alarm Limit: 1 to 200ppm Factory Setting: 35ppm
PPM H2S Alarm Limit 1 to 10ppm Factory Setting: 9ppm
The low and high percent oxygen alarm limits (19.5% and 23%) can not be changed.
Bar-Hole Time. The time can be set from 5 to 60 seconds, factory setting is 15 seconds.
Air-Free CO. Detectors with both CO and Oxygen sensors may be set to display CO on
an “air-free” basis. This choice displays the concentration of CO in a gas free of Oxygen and is
labeled as AFCO. If Oxygen exceeds 16%, CO is reported without correction.
2. FURTHER SETUP PARAMETERS
Power on the Gas-Explorer and while the detector displays “Bascom-Turner Gas-
Explorer”, press the right and center buttons once. A menu of four choices will be displayed:
Cal Due Time 
Pump Current
New Sensor
Power Off
Cal-Due Time. This may be set from 1 to 30 days; factory setting is 30 days.
Pump Current. The “Up” key turns the pump on. The current is should be 50-65 ma.
When the intake is blocked, it should increase to about 220 ma. The Pump Noise test follows
when the “Exit” key is pressed.
The test must be run (with hose, probe, and filter connected) for about 3 minutes to get
meaningful numbers. The noise should be 5.0 or less (pump “Off”) and less than 12 with the
pump “On”
New Sensor. This screen must be run after a new sensor is installed and before the
sensor is first calibrated. When selected, the instrument reverts to a normal start up screen and
proceeds through a mandatory gas calibration screen. 13.

3. CALIBRATION
Calibration must be carried out on a new sensor the next time the instrument is turned on;
with an already installed sensor, the calibration should be carried out at specified intervals. The
A-CAL firmware calibrates the Gas-Explorer using calibration gas available from Bascom-
Turner. The CAL gas required for automatic calibration is Bascom-Turner’s methane and CO
calibration gas containing 2.5 + 0.05% methane and 100 ppm + 2 ppm CO in air. Calibration gas
is provided in a disposable tank containing either 105 liters of gas (Part No. MC-105) or 620
liters (part No. MC-620). The thermal conductivity sensor can be calibrated with pure methane
or natural gas. The oxygen sensor is calibrated with ambient air during power-up.
The calibration gas must be delivered at or near atmospheric pressure to ensure accurate
calibration. For the 105 liter gas tanks Bascom-Turner recommends using a constant flow
regulator (Part No. FR-001) set to the sampling rate of the Gas-Explorer. For the 620 liter gas
tanks Bascom-Turner recommends using an on-demand regulator (Part No. FR-401), which
automatically adjusts its flow to the pumping rate of the Gas-Explorer.
A-CAL Calibration. A-CAL calibration can be carried out either with a One-Gas
routine or by using system gas as well as Bascom-Turner calibration gas. A One-Gas calibration
requires only Bascom-Turner calibration gas (2.5% methane and 100 ppm CO in air) and
automatically calibrates the thermal conductivity sensor with methane.
A-CAL Calibration with System Gas. Power on the Gas-Explorer with the left
“Power-On” button and while the unit displays “Calibrate By …..” press the right “CAL” button.
After a successful autozero, choose the “A-CAL” button, connect natural gas and press the left
“Yes” button. The screen displays “Calibrating” for about a minute and then changes to
“Calibration OK” with a display of readings taken while sampling calibration gas or “Does Not
Calibrate” if calibration was unsuccessful. Three tries are allowed before the screen displays
“Please Service” for 15 seconds and then the instrument turns OFF.
Calibration of the H2S sensor. Proceed as above for pure methane, but use the H2S
calibration gas (10ppm H2S in methane). The instrument will automatically calibrate the thermal
conductivity sensor as well as the H2S sensor.
One Gas Calibration with 2.5% Methane and 100 ppm CO. Power on the Gas-
Explorer with the left “Power-On” button and while the unit displays “Calibrate By …..” press
the right “CAL” button once. After a successful autozero, choose A-CAL. With the unit’s
screen displaying “Connect Calibration Gas”, connect the 2.5% methane and 100 ppm CO in air
calibration gas and press the left “Yes” button. The screen displays “Calibrating” for about a
minute and then changes to “Calibration OK” with a display of % GAS (and ppm CO readings if
it has a CO sensor) or “Does Not Calibrate”, if calibration was unsuccessful. Pressing the left
“Re-Try” button returns to the Calibration screen. If three tries at calibration are unsuccessful,
the screen displays “Please Service” for 15 seconds and then the instrument turns OFF.
Following calibration, the left button leads again to calibration, the right button exits to
the Monitor mode. In both cases, an intermediate screen displays the sensitivity in µw/ppm and
mw/1%. The first quantity (µw/ppm) refers to the Track Gas mode, the second (mw/1%) to the
Monitor mode. If the sensitivity falls below 0.5 µw/ppm, or below 8 mw/1% GAS, the gas
sensor should be changed. In both cases the display reads “Please Change Methane Sensor” and
the instrument is Turned Off.
CAUTION: Automatic calibration presupposes and depends on using Bascom-Turner’s
calibration gas (Part No. MC-105 or MC-620). Do not use a gas of a different
composition for automatic calibration.
14.

PART 3. THE USB INTERFACE
The USB interface is used for docking calibration and for connecting a Gas-Explorer to a
computer for data transfer and for setting operating parameters. The cable required for the
connection is a six foot long, 4-pin, mini BM plug to standard AM plug and is available from
Bascom-Turner (Part No. UC-001).
Docking calibration is described in a separate manual and by prompts on the dock. Data
transfer is described below and in a companion manual for DATA-LINK4Access.
DataLink4Access is an intuitive, easy to use data management system that allows users to
download and organize readings, calibration and GPS data from Gas-Explorers. Each button’s
operation is clearly labeled, and users can navigate from one feature to the next by closing an
operation window or selecting a previously opened tab. With DataLink4Access, users can view
and archive readings, data and calibration records; assign a detector to a specific user; update a
detector’s date and time; and manage all active and retired units.
GPS enabled Gas-Explorer users can use DataLink4Access to preview a single survey or
set of bar holes in Google Earth, use the search by address function to view recent or historical
data for a specific location, or export data for overlay on ArcGIS, MapeFrame or other GIS asset
maps.
15.