Detection, Protection, Innovation

Frequently Asked Questions (FAQs)

  1. Gasurveyor Range: In the Gasurveyor range, what does ‘Check Zero’ mean?
  2. Gasurveyor Range: In the Gasurveyor range, what does ‘Sample Fault’ mean?
  3. Gasurveyor Range: In the Gasurveyor range, what does ‘Zero Fault’ mean?
  4. GT: Can we change from alkaline to rechargeable, or vice versa?
  5. How is the battery life affected by temperature?
  6. How often should instrument filters be changed?
  7. How often should instrument o-rings be changed?
  8. How often should my instrument be calibrated?
  9. What battery type is used with the GMI portable range of gas detectors?
  10. What does CGI mean?
  11. What does CSM mean?
  12. What gas concentrations should I use to calibrate my instrument?
  13. What is the difference between a pumped and diffusion instrument?
  14. What is the IP rating of my instrument?
  15. What range of gases can our GMI instruments measure?
  16. What regulator should I use when calibrating my instrument?
  17. What sensor technology do GMI use in their instruments?
  18. Where should I send my instrument for service / repair / calibration?

1. Gasurveyor Range: In the Gasurveyor range, what does ‘Check Zero’ mean?

This indicates that there may been a zero shift due to the presences of gas. Switch off the instrument and switch on again in fresh air.

2. Gasurveyor Range: In the Gasurveyor range, what does ‘Sample Fault’ mean?

This indicates a problem with the instrument’s flow due to the sample path being blocked, water ingress, a blocked filter or pump failure. This may also indicate a fault with the instrument’s flow fail detection circuitry. The instrument will alarm and the pump will switch off. The sample path should be checked and ‘Switch One’ pressed to clear sample fault and re-start the pump.

3. Gasurveyor Range: In the Gasurveyor range, what does ‘Zero Fault’ mean?

This indicates that the zero is out with its calibration limits. Switch the instrument off and then on again in fresh air. If the fault does not clear, return the instrument for servicing. Please contact us to arrange servicing.

4. GT: Can we change from alkaline to rechargeable, or vice versa?

Yes. Simply replace all three cells of the desired type. Make sure you comply with certification. Refer to user handbook for details.

5. How is the battery life affected by temperature?

Battery life is tested at room temperature normally. However, at very low temperatures, the battery life drops. Batteries stored at high temperatures may lose their charge quicker than at room temperature.

6. How often should instrument filters be changed?

Periodically (dependent on application) or when damaged / dirty / missing.

7. How often should instrument o-rings be changed?

Periodically (dependent on application) or when damaged / dirty / missing.

8. How often should my instrument be calibrated?

We recommend that instruments are calibrated at least every 12 months. Please contact us to arrange re-calibration of your instrument.

9. What battery type is used with the GMI portable range of gas detectors?

Product Battery Type Part Number
V!SA Alkaline pack 66210 / 66538
PS200 Series N/A
Gasurveyor 500 Series Alkaline
Rechargeable NiMH 42114
GT Series Alkaline 67292
Dry cell batteries are supplied as standard. To comply with certification requirements please select the appropriate rechargeable batteries as marked below.
Rechargeable (UL Certified) 67293
Panasonic Rechareable (ATEX Certified) 67294
Acclaim Any D-size batteries
Shipsurveyor Alkaline (LR20 ‘D’ size) Duracell Procell, Duracell Plus, Energizer Ultra, Energizer Industrial
Rechargeable (LR20 ‘D’ size) Uniross 2600mAh NiMH

10. What does CGI mean?

This means that the instrument has a Combustible Gas Indicator mode. In this mode, the pump runs while sampling, ranges are user selectable and alarms are disabled.

11. What does CSM mean?

This means that the instrument has a Confined Space Mode. In this mode, the pump runs continuously, ranges are monitored continuously and the alarms are always active.

12. What gas concentrations should I use to calibrate my instrument?

Please note we are still working on this table at the moment.

Instrument Type Flammable O2 H2S CO CO2 (VOL)
ppm 0-100% LEL 0-10% VOL 0-100% VOL (CO2 Free) 50ppm 500pm 1% 3% 5% 100%
GT 41; GT 44 99125 Methane 99159 Methane N/A 99129 Methane N/A N/A N/A N/A N/A N/A N/A
GT 40; GT 42 N/A 99145
GT43 99143 99145
Gasurveyor 411/421 N/A 99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A N/A N/A N/A N/A N/A N/A
Gasurveyor 511/521
Gasurveyor 3-500/11-500
Gascoseeker 2-500
Oxygas 500
Gascoseeker Acclaim
Shipsurveyor 1 N/A 99159 Methane
99133 Propane
99137 Butane
99141 Pentane
N/A 99129 Methane
99135 Propane
N/A N/A N/A N/A N/A N/A N/A
Shipsurveyor 2 N/A N/A N/A
Shipsurveyor 3 99143 N/A N/A
Shipsurveyor 4 N/A N/A 99164
Shipsurveyor 5 N/A 99145 99164
Shipsurveyor 6 99143 99145 N/A
Shipsurveyor 7 N/A N/A N/A N/A 991694
Gasurveyor 412/422 99125 Methane
99132 Propane
99122 Butane
99140 Pentane
99124 Hydrogen
99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A N/A N/A N/A N/A N/A N/A
Gasurveyor 512/522
ppm Gasurveyor 500
Oxygas P-500
Gasurveyor 423/431 N/A 99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A 99143 N/A N/A N/A N/A N/A
Gasurveyor 523/531
Gasurveyor 424/432 99125 Methane
99132 Propane
99122 Butane
99140 Pentane
99124 Hydrogen
99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A 99143 N/A N/A N/A N/A N/A
Gasurveyor 524/532
Gasurveyor 425/433 N/A 99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A N/A 99145 N/A N/A N/A N/A
Gasurveyor 525/533
Gasurveyor 6-500/6B-500
Gasurveyor 426/434 99125 Methane
99132 Propane
99122 Butane
99140 Pentane
99124 Hydrogen
99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A N/A 99145 N/A N/A N/A N/A
Gasurveyor 526/534
First Responder
Leaksurveyor 99127 Methane 99159 Methane N/A 99129 Methane N/A N/A N/A N/A N/A N/A N/A
Gasurveyor 441/541 N/A 99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A 99143 99145 N/A N/A N/A N/A
Gasurveyor 442/542 99125 Methane
99132 Propane
99122 Butane
99140 Pentane
99124 Hydrogen
99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
N/A 99143 99145 N/A N/A N/A N/A
Gasurveyor 444 N/A 99122 Butane
99137 Butane
N/A N/A N/A 99143 N/A N/A N/A N/A N/A
Gasurveyor 461 N/A 99133 Propane 99133 99135 Propane N/A 99143 N/A N/A N/A N/A
Gasurveyor 487 N/A 99159 Methane
99133 Propane
99137 Butane
99141 Pentane
99126 Hydrogen
N/A 99129 Methane
99135 Propane
99157 N/A 99145 99161 99163 N/A N/A
Gasurveyor 491 Calibrated for Ethanol – Return instrument to GMI for Calibration 99157 99143 N/A 99161 99163 N/A N/A

 

Calibration Gas Measurement T.ex Personal Surveyor 200 (PS200) V!SA PID V!SA V!SA 2
FLAMMABLE 0-100% LEL N/A
Hydrogen Sulphide (H2S) 50ppm 99143 99143 99143 99143
Carbon Monoxide (CO) 100pm 99167 99167 99167 99167
Sulphur Dioxide (SO2) 20ppm N/A N/A 99147 N/A
Nitrogen Dioxide (NO2) 20ppm N/A N/A 99149 N/A
Chlorine (CL2) 10ppm N/A N/A 99151 N/A
Ammonia (NH3) 50ppm N/A N/A 99153 N/A
Nitric Oxide (NO) 100pm N/A N/A 99155 N/A
Carbon Dioxide (CO2) 3% VOL N/A N/A 99163 N/A
Volatile Organic Compound
(PH3 VOC)
50ppm N/A N/A N/A * 99176 N/A

13. What is the difference between a pumped and diffusion instrument?

A pumped instrument includes an internal sampling pump and will draw in a sample automatically when switched on.

A diffusion instrument does not have a pump. Gas samples are diffused in naturally or alternatively drawn in manually using sample line and aspirator bulb.

14. What is the IP rating of my instrument?

Product IP Rating
V!SA Instrument sealed to IP65. Sensing elements, sample inlet and charging socket sealed to IP54
 PS200 Series IP67 (dust-tight and waterproof to 1m)
Gasurveyor 500 Series IP54
GT Series
Acclaim
Shipsurveyor
Leaksurveyor
First Responder
Gascoseeker 2-500
PPM Gasurveyor 500

 

15. What range of gases can our GMI instruments measure?

Please note, gas types will vary depending on instrument type. Please refer to the table below.

Instrument Type Gases Measured
2 Button 500 Series
Gasurveyor 3-500 LEL/VOL
Gasurveyor 6-500 LEL/VOL/CO
Gasurveyor 6B-500 PPM/LEL/VOL/CO
Gasurveyor 11-500 LEL/VOL/O2
4 Button 500 Series
Gasurveyor 511 LEL/VOL
Gasurveyor 512 PPM/LEL/VOL
Gasurveyor 521 LEL/VOL/O2
Gasurveyor 522 PPM/LEL/VOL/O2
Gasurveyor 523 LEL/VOL/H2S
Gasurveyor 524 PPM/LEL/VOL/H2S
Gasurveyor 525 LEL/VOL/CO
Gasurveyor 526 PPM/LEL/VOL/CO
Gasurveyor 531 LEL/VOL/O2/H2S
Gasurveyor 532 PPM/LEL/VOL/O2/H2S
Gasurveyor 533 LEL/VOL/O2/CO
Gasurveyor 534 PPM/LEL/VOL/O2/CO
Gasurveyor 536 PPM/LEL/VOL/CO/H2S
Gasurveyor 541 LEL/VOL/O2/CO/H2S
Gasurveyor 542 PPM/LEL/VOL/O2/CO/H2S
Leaksurveyor PPM/LEL/VOL
First Reponder PPM/LEL/VOL/CO
PPM Gasurveyor 500 SEARCH/PPM/LEL/VOL
Gascoseeker 2-500 LEL/VOL
GT Series
GT40 PPM/LEL/GAS/CO
GT41 PPM/LEL/GAS/O2
GT42 PPM/LEL/GAS/CO/O2
GT43 PPM/LEL/GAS/CO/O2/H2S
GT44 PPM/LEL/GAS
Shipsurveyor
Shipsurveyor 1 LEL/VOL
Shipsurveyor 2 LEL/VOL/O2
Shipsurveyor 3 LEL/VOL/O2/H2S
Shipsurveyor 4 LEL/VOL/O2/CO2
Shipsurveyor 5 LEL/VOL/O2/CO2/CO
Shipsurveyor 6 LEL/VOL/O2/H2S/CO
Shipsurveyor 7 O2/CO2

16. What regulator should I use when calibrating my instrument?

The Balance Flow Regulator (Part No: 99116) is for use with pumped instruments, e.g. Gasurveyors, and should not be used with diffusion instruments, e.g. Personal Surveyors or remote Sensing Heads.

The Direct Flow Regulator (Part No: 99117) is for use with diffusion instruments, e.g. Personal Surveyors, V!SA* or remote Sensing Heads, and should not be used with pumped instruments, e.g. Gasurveyors.

* Note: Make sure that the V!SA pump, if fitted, is switched off before and during the application of calibration gas.

17. What sensor technology do GMI use in their instruments?

Pellistors and Infra-Red technology is used to detect flammable gases.

Electrochemical Cell technology is used to detect toxic gases and oxygen.

18. Where should I send my instrument for service / repair / calibration?

For UK repairs / calibrations, please send your instrument to our service centre at Milton Keynes:

Gas Measurement Instruments Ltd
Service Centre
25 Cochran Close
Crownhill
Milton Keynes
England
MK8 0AJ

For worldwide repairs / calibrations, please contact your territory manager.

Back to Top