Gas Detector Calibration Services


From £25 + VAT

Gas Detection Saves Lives

Our qualified gas detection engineers are certified by Honeywell, so you know your essential safety equipment is in safe hands.

Whether you have 4 or 400 monitors, our service centre and site engineers can repair and recalibrate your personal gas detectors with minimum downtime.

As a BW authorised distributor and repair centre, our engineers are qualified to repair all BW gas monitors, including Microclips, MaxXT, Ultra, Solo, Clip and Micro5. We also calibrate Rae Systems monitors.

Our service vans can attend your site to service your whole fleet of monitors, repairing and calibrating on site. Certificates are produced straight away and are available instantly through our portal.

We replace oxygen cells, LEL sensors, H2S and CO cells. We change screens, cases, batteries and can supply test gas.


   honeywell logo draeger logoriken keiki logo   msa logo   crowcon logo   rae systems logo 


We look after fixed systems by Draeger, BW, Crowcon, MSA, BOC and Analox. Our engineers will visit your site and, using traceable test gas, test and calibrate your fixed system.

Contact us to see how to get your equipment to us and your gas detector will be calibrated within 3 working days of receipt.

Call us now to book a site visit

Back to Calibration

We can help with

  • Personal Gas Monitors from £30
  • Fixed Gas Detection Systems from £POA
  • BW and Honeywell
  • Draeger
  • MSA
  • BOC
  • Crowcon
  • Analox
  • Rae Systems
  • Scott Safety
  • Riken Keiki
  • Neotronics
  • SIL Checks On Site
  • Sensor Replacement from £POA
  • PID Cleaning/Service
  • Filter replacements

* excluding VAT


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Gas Detector Calibration

Calibration is crucial to the performance of safety equipment, so it's essential that you make sure your provider is qualified and certified. Thorcal's engineers have current Level 1 and Level 2 service certificates and Thorcal is an authorised service centre for BW personal gas monitors.

If you have the correct concentrations of traceable test gas, a regulator and appropriate connectors/pipe, you'll be able to perform a calibration or bump check on most monitors by closely following the manufacturer's instructions. However, it's often better to refer your monitors to gas detection specialists such as Thorcal to complete the calibration.

We will thoroughly check the function and condition of your detector, apply traceable test gas and recalibrate the sensors. You'll receive a calibration certificate that's traceable to National Standards.


Bump Checks

If your monitor has an LEL sensor fitted, it's important to "bump check" your monitor before every use. This is because LEL sensors can become "blind" to certain explosive gases if exposed to contaminating chemicals.

You bump check your monitor by applying gas to the sensors and making sure they alarm at the appropriate levels.

This is not the same as a calibration, as it's just a check on the function of the sensors, not a readjustment based on the concentrations of gas.


Calibration Gas

Test gas should be traceable to National Standards and come with a certificate of conformity. You should be able to see the certificate number from the test gas used on your calibration certificate under traceability information.

Thorcal can supply all concentrations of test gas and calibration gas. Contact us with your requirements.


PID Service

Does your monitor have a PID sensor to see exotic gases? PID (photoionisation devices) use ultraviolet light to detect gases that aren't detectable by other methods. 

While PID sensors tend to have a much longer lifespan than electrochemical sensors, the lens to the PID lamp needs periodic cleaning and servicing to ensure it operates correctly.

Thorcal can service all PIDs during the calibration process.


Firmware Updates

Thorcal will apply the most recent firmware updates to your monitor during the calibration.

Pumped or Diffuse Gas Detectors

Monitors like the BW Microclip series or Crowcon T4 use the diffusion method of gas detection. This means that the monitor doesn't actively draw in the gas from the atmosphere, it only detects what is diffusing around it. These detectors are meant to be worn on the breast, near to the mouth. This way your detector is exposed to the same atmosphere are you are.

Pumped units have a small pump module that actively draws in the atmosphere. You may want to use these to sample gas from a tank, an enclosed space using a tube attachment before entering, or from a drain to detect any leaks.


Fixed Gas Detection Systems

Thorcal's site engineers have worked on Crowcon, Draeger, Analox, BOC and other leading brands of fixed gas detection system. 

We can provide short notice callout to your system to assess faults, or calibrate fixed sensor heads. We calibrate LEL detectors, SO2, Ammonia, Hydrogen, O2 and others.

Our gas engineers are experienced in SIL checking fixed systems, ensuring integrity of your gas detection equipment.


Hire Gas Detectors

We keep a fleet of personal gas monitors for short, long term and permanent hires. Find out more about how you could save money by hiring gas detectors from us.


Buy Gas Monitors

As an authorised distributor for Honeywell safety products, Thorcal is able to source any monitors you may need, including all parts and accessories. Make Thorcal your first stop for buying gas detection equipment. Find out more.


Gas Detector Repair

Most gas detection sensors have an operational lifespan, after which they expire and need to be replaced.

Thorcal carries stocks of all parts for the leading manufacturers of gas monitors and can replace failed sensors.

If your monitor fails calibration due to a failed sensor, we'll produce a fault report and quote for the repairs and gain your approval before going ahead.


Filter Replacement

Thorcal will inspect the sensor filters on your personal gas monitor and quote you for replacement if needed.

Sensors are sensitive to water ingress or contamination by damaging chemicals. If the sensor port is blocked by dirt, the detector won't be exposed to the atmosphere, so will be unable to see gas.

Filters are one of the most inexpensive parts on a gas monitor to replace, yet very important if your monitor is to function correctly.