UKAS Calibration Service

Calibration of pressure, vacuum, gas flow, temperature and electrical

Since 1976, Chell Instruments has provided customers with a comprehensive calibration service, covering all the instrumentation we supply.

Since 1999, we have offered a full ISO/IEC17025:2017 accredited calibration service through our laboratory (number 0687).

We specialise in calibrating:

  • Pressure (absolute & differential)
  • Vacuum
  • Gas flow rate – with supporting parameters of temperature and electrical DC

We provide calibration with some of the lowest available uncertainties, helping our customers enjoy overall lower uncertainties when aggregated with their own in-house uncertainties.

By using Chell Instruments for periodic calibration, many organisations in strategic industries including pharmaceuticals, aerospace, custody transfer, aerodynamics and nuclear energy have been able to reduce their uncertainties.



UKAS Calibration Price Matrix


UKAS On-Site Calibration Price Matrix


UKAS Schedule of Accreditation


UKAS ISO:17025 2017 Certificate


SafeContractor Accreditation 2018-19

Pressure Calibration


Using independent traceability chains and fundamentally different pressure principles, our calibration standards provide unrivalled confidence.

Our primary PG7601 Pressure Balance (deadweight tester) system offers some of the lowest uncertainties in the UK and is cross-checked against our primary 110inch Schwien Merco-Master Manometer with a 5ppm agreement tolerance.

Our working standards use state-of-the-art digital resonant quartz pressure controllers with portable flight cased systems.

Chell Instruments has 12 decades of pressure capability from 0.000001 millibar to 690 bar. 


Resonant Quartz or Silicon Transducers |  Precision Pressure Generators and Transfer Standards | Air Data and Pitot-Static Test Sets | Electronic Pressure Scanners | Capacitance Diaphragm Gauges | Precision Barometers | Digital Pressure Indicators and Calibrators | Airspeed Indicators | Altimeters and Rate of Climb (vertical speed) Meters | Micromanometers

Pressure ranges for each sensor types

Vacuum Calibration


To provide our clients with confidence, our vacuum standards are Capacitance Diaphragm Gauges (CDG). Each has over thirty years continuous annual calibration history, with traceability directly from two national measurement institutes – NPL, Teddington and PTB, Berlin.

We carry out regular in-house inter-comparison checks between different range CDGs:

  • CDGs and Spinning Rotor Gauges at the low-pressure
  • CDGs and a Schwien Merco-Master manometer at barometric pressure

These inter-comparisons using overlapping standards have different measurement technologies and traceability, providing a very high level of confidence in our vacuum calibration from 1E-06 mbar to atmosphere.


Thermocouple Gauges | Capacitance Manometers and Capacitance Diaphragm Gauges | Convection Gauges | Full-Range and Triple Full-Range Gauges | Pirani Gauges | Spinning Rotor Gauges | Cold and Hot Cathode Gauges | Bayard-Alpert and Penning Gauges | Inverted Magnetron Gauges | AIM, CDG and SRG Gauges | Gas Friction Manometers and Gauges

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Flow Calibration


For flow meter calibration, we use a mixture of state-of-the-art molbloc laminar flow and sonic nozzle standards, with traceability to NIST and VSL Dutch Metrology Institute.

Chell has 7 decades of air flow rate calibration capability from 0.001 to 12,500 litre/min.


Mass Flow Meters (MFM) | Mass Flow Controllers (MFC) | Coriolis Flow Meters | Variable Area Flow Meters (Rotameters)  | Dry Cal Provers

Electrical and Temperature Calibration

To support the low uncertainties achieved by our laboratory for pressure, vacuum and gas flow, we offer UKAS accredited calibrations of low voltage DC and current, elapsed time and electrical simulation of temperature indicators.

In addition, Chell Instruments is accredited for the temperature calibration of probes between -20°C and +100°C.

On Site Calibration

We can perform calibrations at your location, dramatically reducing downtime by eliminating the need to return measuring instruments to our calibration laboratory.

A wide variety of industries are supported, including environmental, pharmaceutical, process control, laboratory, power generation, aerospace, brewing, thermal spraying and motor sport.

We’ve conducted calibrations around the world – even as far as the Falkland Islands!

A key benefit of this approach is that instruments are calibrated in their working environment and attitude, thus reducing orientation or temperature errors.