How to Choose a SAC-SINGLAS Accredited Calibration Lab in Singapore

Choosing a calibration lab in Singapore comes down to five checks: does their accreditation scope actually cover the instruments and parameters you need, not just their accreditation status in general; what is their real turnaround time; can they calibrate on-site if your equipment cannot be removed; do they publish evidence of what they cover rather than asking you to take their word for it; and does their certificate show the specific content, as-found and as-left readings, and stated uncertainty, that your quality system needs. An accreditation logo on a website tells you almost nothing on its own. This guide walks through what to actually verify before you commit, so you can evaluate any provider on the same criteria, including us.

Check the accreditation number and scope, not just the logo

A logo is a marketing asset. What actually matters is the accreditation number behind it and the specific scope of accreditation tied to that number, because SAC-SINGLAS accreditation to ISO/IEC 17025 is not a blanket "this company is accredited" statement, it is a defined, published list of exactly which parameters, ranges and methods a lab is accredited to perform. A lab can be genuinely SAC-SINGLAS accredited and still not be accredited for the specific instrument or range you need. Ask for the accreditation number and the current published scope, and check that your instrument type and its range fall within it. As an example of what a real accreditation number and scope look like, Unitest's SAC-SINGLAS accreditation is LA-2023-0845-C, with a published scope covering specific temperature, humidity and electrical parameters and ranges. Any provider you evaluate should be able to show you the equivalent for their own accreditation, not just the mark.

Check turnaround time, honestly stated

Turnaround varies by instrument type, whether the work is in-lab or on-site, and how busy the lab is at the time you ask. Ask for a realistic standard turnaround and whether an express option exists, then judge whether it fits your operational calendar, especially if a piece of equipment coming out of service for calibration affects production or a validated process. A provider who cannot give you a specific number, or who quotes an unrealistically fast time with no qualification, is worth a second look. As a reference point, our own standard turnaround is 5 to 7 working days, with a 2 to 3 day express option where needed.

Check whether they can calibrate on-site, not just in the lab

Some instruments cannot practically be removed from where they are installed: a permanently wired power meter, a fixed process calibrator, a stability chamber that cannot come out of a validated study, a duct-mounted building-management sensor. If your fleet includes fixed equipment, ask specifically whether the lab offers on-site calibration with reference standards brought to your facility, and what measurement uncertainty that achieves compared with in-lab work. A lab that only calibrates in a fixed laboratory location cannot serve that part of your fleet at all, regardless of how good their lab work is.

Check whether they actually calibrate the specific instrument types you need

Calibration providers specialise. A lab strong in electrical instruments is not automatically equipped for humidity or pressure work, and vice versa. Rather than asking a general "do you do calibration," ask for the specific instrument categories and parameters on their published scope, and cross-check that list against your actual fleet: multimeters, pressure gauges, temperature sensors, humidity probes, tachometers, timers, whatever you actually own. A provider who is upfront that a particular instrument or parameter falls outside their scope, and says so before quoting rather than after the fact, is generally more trustworthy than one who implies broad coverage without specifics. See our own calibration services in Singapore for an example of how a scope should be laid out clearly by instrument type.

Check what the certificate actually contains

The certificate is the deliverable your quality system will rely on, sometimes for years, so its content matters more than the paperwork's appearance. A compliant, accredited certificate should show the accreditation mark and number, the specific calibration points across the instrument's working range, both as-found (before any adjustment) and as-left (after adjustment) readings, the expanded measurement uncertainty stated at each point, a traceability statement linking the reference standards to national measurement standards, clear instrument identification including make, model, serial number and your own asset ID, and the calibration date with the recommended due date. If a sample certificate is missing as-found data, states no measurement uncertainty, or is vague about traceability, that is a real gap, not a formatting quirk. Ask to see a sample certificate before committing, from any provider you are evaluating.

Ask what happens when an instrument fails calibration

A provider's answer to "what if it doesn't pass" tells you a lot. A defensible process reports the as-found failure honestly on the certificate, discusses whether adjustment is possible and appropriate, and if the instrument is adjusted, records the as-left result separately so you can see both states. A lab that quietly adjusts every instrument to pass without documenting the as-found condition is hiding exactly the information your quality system needs if a safety or product decision was made using that instrument before the failure was caught.

A short checklist for evaluating any calibration provider

• Accreditation number and published scope, checked against your specific instrument list and ranges, not assumed from a logo.
• A stated, realistic turnaround time, with an express option if you need one.
• On-site capability if any of your fleet is fixed or cannot be removed.
• A published or requestable scope showing exactly which instrument types and parameters are covered.
• A sample certificate showing as-found and as-left readings, stated measurement uncertainty, and a traceability statement.
• A clear, honest answer about what happens when an instrument fails, and whether as-found data is preserved.

Where Unitest fits, honestly

We are SAC-SINGLAS accredited to ISO/IEC 17025 under LA-2023-0845-C, with a published scope covering specific temperature, humidity and electrical parameters and ranges, both in our lab and on-site. If your instrument or the parameter you need is not on our current accredited schedule, we will tell you before quoting, or refer you elsewhere, rather than implying coverage we cannot support. See our full range of calibration services in Singapore for what falls within our scope, or contact us with your specific instrument list and we will confirm what we can and cannot cover.