Gas Detector, Gas Monitor & GDU Calibration Services

Where gas detection forms part of your safety controls, the equipment needs to be suitable, maintained and working correctly. For confined-space monitoring, HSE guidance calls for calibration and testing in line with manufacturer recommendations or a schedule identified through risk assessment.

Keep calibration records alongside your site procedures. A certificate supports those records, but does not by itself establish that a site is safe to enter.

Follow the calibration interval specified for your detector and your site risk assessment. If your detector’s instructions specify six months, use that interval unless your risk assessment or operating conditions require earlier calibration.

Sensor type, working conditions and use can affect the schedule. Share your model and how it is used, and we can advise on a suitable calibration plan.

A bump test checks that the detector responds to gas; it does not measure its accuracy. Calibration checks and adjusts the detector’s response using known test-gas concentrations and provides traceable results. Follow the manufacturer’s instructions and your site procedures for both. Keep calibration records with your equipment documentation.

We inspect the unit, apply a known concentration of test gas, check the sensor response, adjust the readings where required and verify stability before issuing certification. If the detector needs a sensor, filter or repair, we’ll quote before carrying out any additional work.

We calibrate for common industrial gases including O₂, CO, H₂S, and LEL (flammable gases), using manufacturer-specified test concentrations. Multi-gas detectors are adjusted and verified against all active sensors. We can also handle specialist mixes (e.g. NO₂, SO₂, VOCs) used in industrial and environmental applications.

We regularly calibrate MSA, Dräger, BW Honeywell (including Microclip units), Crowcon, MultiRAE and more. If your model isn’t listed, just ask – we can usually accommodate it or suggest a suitable alternative.

We’ll flag any issues during inspection and send you a no-obligation quote. We don’t replace parts without permission – no hidden charges, no surprises.

Fixed gas detection systems require full functional verification and flow-rate checks as part of calibration. We test alarm setpoints, check response times, and ensure your system communicates correctly with control panels or alarm beacons.

Yes. We work with contractors, engineers and health and safety leads managing high-risk sites. We calibrate against the relevant manufacturer requirements and provide records for your equipment files.

The detector’s suitability, gas selection and entry procedures must also match your site risk assessment. Calibration alone is not clearance to enter a confined space.

Yes. We regularly calibrate multiple gas monitors and GDUs during a single visit.

This is ideal for sites with several detectors, safety managers overseeing multiple teams, or organisations managing equipment across different departments.

We’ll plan the visit to minimise downtime and can combine calibration with other compliance services where required.

Yes. We offer fully mobile GDU calibration across the UK. We’ll come to your site, minimise disruption, and handle everything on the day – certificates included.

Workshop turnarounds typically take 2–5 working days. For urgent jobs, we aim to complete fast-track calibration within 24 hours, subject to availability. Contact us to confirm the turnaround for your equipment or arrange an on-site visit.

Yes. Many clients schedule gas monitor calibration alongside Face Fit Testing, LEV Testing or Breathing Air Quality Testing. It’s a simple way to reduce downtime and keep multiple compliance requirements up to date in one visit.

Yes. Every calibration includes a digital certificate with test results, gas types used, engineer ID, calibration date, next due date and traceability to national standards. These records are suitable for audits, insurance checks, confined space permits and internal compliance files.

Absolutely. Every calibration includes a digital certificate showing test results, gas types used, engineer ID, and compliance to relevant standards – perfect for audits.

Yes – we track your equipment’s due dates and notify you ahead of time, so you don’t fall out of compliance or scramble for paperwork.

Yes – Velocity Safety provides Gas Detection Unit calibration across the North West, including Blackburn, Preston, Bolton, Manchester, Burnley, and Lancaster. Our engineers offer on-site visits or fast courier turnaround from our Blackburn calibration workshop, with certificates issued the same day where possible

We also support national frameworks and multi-site clients across the UK.

Absolutely. We calibrate Gas Detection Units (GDUs) for teams across the UK – from Leeds and Birmingham to Dundee and Aberdeen. Whether your site is in Yorkshire, Scotland, or the South East, our mobile engineers can attend on-site or handle courier-based calibration through our Blackburn facility.