Questions
Calibration FAQ: straight answers on accredited calibration in Singapore
The questions quality managers, engineers and buyers ask us most often, answered plainly. Everything below reflects what Unitest Instruments actually holds and actually does: our SAC-SINGLAS accreditation, what is on our certificates, what we can calibrate at your site, and how long it takes. If your question is not here, ask us and we will answer it directly.
The short version
Three things most people are really asking
Most enquiries come down to the same three concerns: is the certificate good enough for an audit, can you come to us, and how long will the instrument be gone.
Accredited to ISO/IEC 17025:2017
SAC-SINGLAS Accreditation No. LA-2023-0845-C, covering electrical, temperature and pressure disciplines.
On-site covers temperature and pressure
On-site calibration is available islandwide for temperature and pressure instruments. All other disciplines are calibrated at our laboratory.
5 to 7 working days standard
Express service of 2 to 3 working days on request. Free collection and delivery within Singapore above S$300.
Full answers
Calibration questions, answered in full
Each answer states what we can evidence. Where something depends on your specific instrument, we say so rather than generalising.
Is Unitest a SAC-SINGLAS accredited calibration laboratory?
Yes. Unitest Instruments is accredited to ISO/IEC 17025:2017 under SAC-SINGLAS Accreditation No. LA-2023-0845-C. The accredited scope covers electrical, temperature and pressure disciplines, and accredited certificates are recognised internationally through the ILAC Mutual Recognition Arrangement. A copy of our current scope of accreditation is available on request.
Will your calibration certificate pass my ISO 9001 / ISO 17025 audit?
Our accredited certificates are issued under SAC-SINGLAS Accreditation No. LA-2023-0845-C to ISO/IEC 17025:2017, so they carry independently assessed measurement traceability rather than an in-house claim. Each certificate records the instrument make, model and serial number, the calibration date and due date, the reference standards used with their own traceable reference numbers, whether the result is As Found or After Adjustment, and the expanded measurement uncertainty at k=2 (approximately 95% confidence). It is signed by our Laboratory Engineer and Technical Manager and issued under ILAC-MRA mutual recognition. Where an instrument or range falls outside our accredited scope, we tell you before we start and issue a traceable non-accredited certificate instead.
What does a Unitest calibration certificate include?
Equipment details (manufacturer, model and serial number), the calibration date and the due date, the reference standards used with their own traceable reference numbers, the calibration type (As Found or After Adjustment), and the expanded measurement uncertainty at k=2, approximately 95% confidence. Certificates reference our calibration procedure UNI-T001, are issued in accordance with the SAC terms of accreditation, and are signed by the Laboratory Engineer and the Technical Manager. A calibration report without an authorising signature is not valid.
What is the difference between accredited and non-accredited calibration?
Accredited calibration is independently assessed for technical competence, method and traceability, and the stated measurement uncertainty is reviewed by the accreditation body. A non-accredited certificate has no third-party assurance behind its methods or its uncertainty. At Unitest the same reference standards are used for both; what differs is the SAC-SINGLAS endorsement. For audit purposes, accredited calibration is what counts, and we offer traceable non-accredited calibration where an instrument, range or site condition falls outside our accredited scope.
Do you offer on-site calibration in Singapore?
Yes. We calibrate at our laboratory or on-site at your facility, islandwide, including the Jurong, Tuas and Changi industrial areas. On-site calibration covers temperature and pressure only: temperature ovens, chillers and freezers, PRT and thermocouple sensors, temperature indicators and transmitters, thermohygrometer probes, dry-well calibrators, and low-pressure, differential-pressure and pneumatic pressure instruments. Every other discipline, including electrical calibration, is carried out at our laboratory. On-site work follows the same ISO/IEC 17025 procedures as in-lab work and is issued with the same traceable certificate.
What is the difference between a calibration certificate and a calibration report?
A calibration certificate formally records the measurement results, the reference standards used, the measurement uncertainty and the traceability chain for accreditation purposes. A report is a less formal summary. Accredited work is always issued with a certificate, signed by our Laboratory Engineer and Technical Manager, and a calibration report issued without an authorising signature is not valid.
What is your typical turnaround time?
Standard turnaround is 5 to 7 working days from receipt of your instruments to calibrated and certified return. An express option of 2 to 3 working days is available on request; contact us to confirm availability before sending your instruments. Collection and delivery within Singapore are complimentary for orders above S$300.
Can you calibrate instruments sent from outside Singapore?
Yes. We service overseas orders. Send your equipment to our laboratory at 18 Boon Lay Way, #04-93, Tradehub 21, Singapore 609966 and we will return it calibrated and certified. Contact us before shipping so we can confirm capability and turnaround for your instrument list.
Still deciding
Not sure which service you need?
If the instrument is critical to a controlled process and your auditor asks for evidence of traceability, you want accredited calibration. Our scope of accreditation lists every accredited measured quantity and its calibrated range, so you can check your instrument against it before you send anything in. If your instrument, range or site condition falls outside that scope, we can still calibrate it as a traceable non-accredited service, and we will tell you which one applies before we start rather than after the certificate is issued.
If the instrument is fixed in place, too heavy to move, or too critical to lose for a week, ask about on-site calibration. Our on-site scope covers temperature and pressure: ovens, chillers and freezers, PRT and thermocouple sensors, temperature indicators and transmitters, thermohygrometer probes, dry-well calibrators, and low-pressure, differential-pressure and pneumatic pressure instruments. Electrical work is done at the laboratory, where the reference standards live.
If you are not sure what you have, start with Find Your Instrument and send us the make and model. Our engineers will confirm whether it falls within our accredited scope or can be calibrated as a traceable service, and quote ranges, points and turnaround for it. You can reach us on +65 6659 8878 or at sales@unitestinst.com.