SAC-SINGLAS Accredited · ISO/IEC 17025
Radiation Thermometer & Pyrometer Calibration
Unitest provides SAC-SINGLAS accredited radiation thermometer and pyrometer calibration in Singapore from 35 C to 500 C, under method UNI-T008, against a traceable reference blackbody source, with measurement uncertainties (CMC) from 1.1 C to 3.7 C at an emissivity setting of 0.90 to 1.00 and a spectral band of 8 to 14 micrometres.
What is radiation thermometer calibration?
Radiation thermometry is the formal discipline of measuring temperature from thermal radiation. Radiation thermometer calibration verifies and documents how accurately a pyrometer reads temperature from a distance. The instrument is aimed at a reference blackbody source, a cavity of known, controlled temperature and near-unity emissivity, the source is set to each calibration point, and the pyrometer's reading is compared against the true temperature. The deviation is recorded across the range and reported with its measurement uncertainty, under method UNI-T008 from 35 C to 500 C.
Industrial pyrometers, emissivity and spectral band
Three parameters govern a meaningful radiation thermometry calibration, and Unitest states all three on the certificate. The reference is a traceable blackbody source. The emissivity setting is 0.90 to 1.00, matching the high-emissivity industrial surfaces most process pyrometers are configured for. The spectral band is 8 to 14 micrometres, the long-wave infrared region in which many general-purpose radiation thermometers operate. On a real furnace or kiln wall, emissivity is the single biggest source of error: a surface that radiates less efficiently than the pyrometer assumes will read low, so calibrating against a known blackbody at a defined emissivity separates instrument error from process surface effects.
This page is aimed at industrial and process radiation thermometry: fixed-mount pyrometers, radiation pyrometers and continuous process infrared thermometers built into furnaces, kilns and production lines. For handheld infrared thermometers and IR guns used for food safety, HVAC and facilities spot checks, see our infrared thermometer calibration page, which covers the same accredited method for portable instruments.
Accredited range and when to calibrate
Unitest's accredited non-contact range runs from 35 C to 500 C under method UNI-T008, with CMC uncertainties from 1.1 C at the low end up to 3.7 C at the top of the range. Standard turnaround is 5 to 7 working days, with a 2 to 3 day express option, and free collection and delivery across Singapore for orders of S$300 and above. For a fixed-mount process pyrometer we can arrange on-site calibration so the sensor is checked in place with minimal downtime.
Process pyrometers drift through optical contamination, window fouling, detector ageing and mechanical or thermal shock, and because they often run unattended, an out-of-tolerance sensor can bias a whole production run before anyone notices. Calibrate a new instrument before it goes into service, then at least annually, more often for critical high-temperature process roles, and after any repair or exposure to out-of-range conditions. An accredited certificate is how you keep your high-temperature process measurements audit-ready.
What we calibrate
Radiation Thermometer instruments we calibrate
- Fixed-mount industrial pyrometers
- Radiation pyrometers
- Process infrared thermometers
- Furnace & kiln pyrometers
- Heat-treatment & forging pyrometers
- High-temperature non-contact sensors
Accredited under SAC-SINGLAS LA-2023-0845-C. View our accreditation & scope →
Questions
Radiation Thermometer calibration FAQ
Is radiation thermometer and pyrometer calibration SAC-SINGLAS accredited?
Yes. Non-contact radiation thermometer and pyrometer calibration is on our SAC-SINGLAS accredited schedule under method UNI-T008, from 35 C to 500 C, against a traceable blackbody source. Certificates are issued under our ISO/IEC 17025 accreditation, LA-2023-0845-C, with stated measurement uncertainty at each point.
What is the difference between a radiation thermometer and an infrared thermometer?
Metrologically they are the same instrument: both measure temperature from the infrared radiation a surface emits, and both are calibrated by the same method against a reference blackbody. The terms differ by context. Radiation thermometer and pyrometer are the usual names for fixed-mount and process instruments in industrial high-temperature measurement, while infrared thermometer or IR gun usually describes a handheld spot-check tool. If you are calibrating a handheld infrared thermometer or IR gun for food safety, HVAC or facilities work, our infrared thermometer calibration page covers that instrument directly.
Can you calibrate high-temperature pyrometers above 500 C?
Our accredited radiation thermometry scope covers 35 C to 500 C under method UNI-T008. Many pyrometers used in metal, glass and furnace processes are specified well above 500 C. We can calibrate such an instrument across our accredited range, and the certificate will state exactly which points are covered. If you need calibration at temperatures above 500 C, tell us the instrument and the range you require and we will confirm what we can and cannot cover before you commit, rather than overstate our scope.
What emissivity and spectral band do you calibrate at?
We calibrate at an emissivity setting of 0.90 to 1.00 against a reference blackbody source, over a spectral band of 8 to 14 micrometres. This matches how most general-purpose radiation thermometers and process infrared sensors are built and used, on high-emissivity surfaces in the long-wave infrared region. Emissivity is stated on the certificate because it is the largest real-world source of error in radiation thermometry.
How often should an industrial process pyrometer be calibrated?
At least once every 12 months for general use, and every 6 months for critical high-temperature process-control roles. Recalibrate after any window fouling, optical contamination, mechanical or thermal shock, or repair. Your quality management system, for example ISO 9001 or a process control specification, may set a shorter interval. We can send a recall reminder when each pyrometer is due.
Range information
Non-contact radiation thermometer / pyrometer, method UNI-T008. Range 35 C to 500 C, CMC 1.1 C to 3.7 C. Emissivity 0.90 to 1.00, spectral band 8 to 14 micrometres. Refer to the SINGLAS schedule LA-2023-0845-C for the full accredited range.
Accredited ranges
Radiation Thermometer calibration ranges & measurement uncertainty
The parameters, ranges and calibration & measurement capability (CMC) below are taken from our SAC-SINGLAS Schedule of Accreditation (LA-2023-0845-C, to ISO/IEC 17025). CMC is the smallest measurement uncertainty we can achieve under accredited conditions.
Non-Contact Temperature Infrared Thermometer / Thermal imager (Emissivity: 0.90 – 1.00; Spectral Band: 8 to 14 µm)· UNI-T008 Rev:0
| Range / measured quantity | Measurement uncertainty (CMC) |
|---|---|
| 35 °C – 100 °C | 1.1 °C |
| >100 °C – 200 °C | 2.1 °C |
| >200 °C – 350 °C | 2.6 °C |
| >350 °C – 500 °C | 3.7 °C |
Related
Other calibration disciplines
Non-Contact Temperature (IR) Calibration
Learn more →Infrared Thermometer Calibration
Learn more →Temperature Calibration
Learn more →Guides & resources
Radiation Thermometer calibration guides
Will Your Temperature Cert Survive the Audit? How Often to Calibrate Temperature Sensors
The auditor's checklist for a temperature calibration certificate, accreditation logo, traceability chain, stated uncertainty, in-scope range and interval, plus how to set defensible calibration frequencies for RTDs, PRTs, thermocouples, thermistors and infrared thermometers in Singapore.
Read guide →Infrared and Radiation Thermometer Calibration: Emissivity, Blackbody and Accuracy
Why non-contact is not no-calibration: a Singapore guide to infrared and radiation thermometer calibration, how emissivity, distance-to-spot and blackbody traceability drive accuracy, and the false confidence an uncalibrated IR reading creates.
Read guide →Temperature Sensor Types: RTD vs PRT vs Thermocouple vs Thermistor vs Infrared
A Singapore engineer's guide to temperature sensor types: how RTDs, PRTs, thermocouples, thermistors and infrared thermometers differ in accuracy, range and drift, and how each is calibrated to a traceable, audit-ready standard.
Read guide →