CalibrationKey Takeaways
- “Load cell calibration” names two different jobs: calibrating a whole weighing system with test weights, and calibrating a load cell on its own as a force standard to ISO 376. Say which one you need before you compare quotes.
- Hand torque tools follow ISO 6789, with a default retest within 12 months or 5,000 use cycles, and sooner after a drop or overload.
- Accreditation is listed per instrument and range. Al Saqr Engineering’s EIAC entry, read on 16 October 2026, lists hand torque tools from 9.04 to 813.5 N·m and scales up to 1,000 kg on site. It names no force or torque transducer line, so ask any provider what your certificate will state.
Industrial buyers often send one enquiry for “load cell and torque calibration” and then receive quotes that cover different things. A weighbridge, a tensile-test rig and a fleet of torque wrenches each need their own method, reference equipment and certificate. This guide shows how to specify each job, how to read a provider’s accredited scope, and what to ask before you order. Our service details are on the load calibration and torque calibration pages.
What Does Load Cell Calibration Actually Mean?
Two jobs share the name, and they use different methods.
- A load cell inside a weighing system (a scale, hopper, tank or platform) is normally calibrated with the rest of the system: the indicator, the cell or cells and the structure, loaded with certified test weights. The reference guideline for this is EURAMET cg-18 for non-automatic weighing instruments, which EIAC’s listing for our scales and balances cites.
- A load cell or force transducer used as a force standard, or built into a test machine, is calibrated by itself against a reference force. ISO 376 covers this. It classifies instruments as 00, 0.5, 1 or 2 and applies to load cells, proving rings and dynamometers. According to Morehouse’s guide to the standard, a certificate can be valid for no more than 26 months.
The accuracy classes of load cells made for weighing, defined in OIML R60, are a separate topic, covered in our guide to load cell and electrical calibration.
What Should a Load Cell Calibration Enquiry Include?
Vague enquiries get vague quotes. Put these six items in yours:
- The item: a load cell alone or a complete scale, with make, model and serial number.
- Capacity and unit: kg, tonnes or kN, and whether the cell works in tension, compression or both.
- The accuracy you need: an ISO 376 class or a target uncertainty, not “high precision.”
- Where the work happens: tanks, hoppers and fixed platforms can’t travel, so ask what is possible on site versus in the laboratory.
- Reference weights: ask who supplies them, what they’re traceable to, and how much of your capacity the test loads reach.
- Data you want back: “as found” and “as left” readings, uncertainty and the accreditation body’s symbol.
How Often Should Torque Tools Be Calibrated?
Click, dial, beam and setting wrenches fall under ISO 6789. Part 1 sets the manufacturing and conformity requirements, and Part 2 sets the calibration method. For a tool in service, retesting should take place within 12 months or 5,000 use cycles of it being put into use, according to Norbar’s summary of the 2017 edition. Treat that as a default. A tool that has been dropped, overloaded or is giving odd readings should go in at once, and a stricter quality system can set a shorter interval.
Torque transducers and analysers, the instruments that serve as a workshop’s own reference, are a different job. They’re calibrated as static torque measuring devices, and EURAMET cg-14 is the usual guideline.
A hand wrench below 9.04 N·m or above 813.5 N·m sits outside these listed ranges, and so does any tool that isn’t an indicating or setting hand tool. Check your tool’s range against the lines before you assume it’s covered.
How Do You Read a Provider’s Accredited Scope?
Accreditation attaches to specific instruments and ranges, so a general claim of ISO 17025 accreditation tells you little about your job. Our guide to verifying an ISO 17025 accredited laboratory explains how to find the entry. Al Saqr Engineering’s EIAC entry, read on 16 October 2026, lists hand torque tools, weighing scales and balances up to 1,000 kg, and test weights from 1 mg to 20 kg, among other disciplines.
Scales are listed up to 1,000 kg, so a weighing system rated above that is outside the listed range. Work outside a listed line can still be done and traced to national standards, but the accreditation doesn’t cover it, and the certificate should say so. Ask any provider, us included, to confirm in writing which category your job falls into before you order. It’s a reading of a public entry, and the directory remains the authority.
Which Questions Should You Ask Before You Order?
- Is my instrument type and range on your accredited scope, and which line covers it?
- Will the certificate carry the accreditation body’s symbol, the uncertainty and the as found and as left readings? Our page on the calibration certificate shows what to look for.
- Is the work done at the laboratory or at my site, and who supplies the reference weights?
- What retest interval do you recommend for my duty, and what happens if a tool fails?
Enquiring about scales, balances or test weights instead? The same questions apply, and our mass and balance calibration page covers that service.
Frequently Asked Questions
There's no single interval. For a load cell used as a force standard, ISO 376 limits a certificate's validity to 26 months, according to Morehouse. For scales, set the interval by use, load history, risk and your auditor's requirement.
On Al Saqr Engineering's EIAC entry, the hand torque tool lines are listed for the laboratory only, so tools go in for calibration. Scales are listed for customer premises.
Only instruments that fall within a listed scope line, at the listed range and location. For anything else, ask whether the work is accredited, traceable only, or subcontracted, and what the certificate states.
Request a Quote
Send your instrument list with types, capacities, ranges, quantities and locations. We’ll confirm which lines of our scope apply and what the certificate will state.