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The Instron® range of capabilities reflects our commitment to be the leading force calibration service in the industry. As the first materials testing company to use strain gauge load cell technology and as the leader in providing high-accuracy testing instruments, we take pride in our knowledge of force measurement and calibrations of the highest quality.

To assure safe and effective handling of material and equipment returned to our facilities for calibration and verification, we follow a Returned Material Authorization and documentation process (RMA).

We perform calibrations and verifications to internationally recognized standard methods, including ASTM E74 and ISO 376 for calibration of standards.

Best Achievable Classification

Calibration Method

Up to 24,000 lbf
(Tension and Compression Mode)

Up to 1,000,000 lbf
(Compression Mode Only)

Class AA
Class A
ISO 376
Class OO
Class 1

Calibration of Secondary Standards


This standard defines secondary standards as force measuring instruments calibrated by Primary Standards (Dead Weights) and they are primarily used in the calibration of other force measuring devices. The laboratory can provide these calibrations to meet the Class AA requirements of ASTM E 74 up to 130,000 lbf in both tension and compression mode.

ISO 376

The laboratory can provide calibration of standards to meet Class OO up to 240,000 lbf in tension and compression modes and Class 1 up to 1,000,000 in compression mode.

Calibration of Working Standards

The lab calibrates the “working standard” transducers used by our field specialists and can provide this service to our customers. Because of the low uncertainties associated with our deadweight stacks (compared to other labs that use secondary standard load cells), we are able to shorten the “chain of calibration” and equip the field with load cells calibrated with a lower uncertainty than is typical. For no extra cost, we can verify your testing machine is 0.5% instead of the 1% specified in ASTM and ISO standards.

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Capabilities for the Calibration of Tup's

The laboratory can calibrate the force measuring element of Dynatup® impact testing system, a Tup, up to 225,000 lbs. This calibration is recommended every 6 months or 5,000 impacts, and provides the user with the calibration factors necessary to properly analyze the Tups output.

Available Factory Verification Services

Type Standard Description
Force Verification


ISO 376

Calibration of Secondary Standards to 240,000 lbf


ISO 376

Calibration of Working Standards to 1,000,000 lbf
Tup Calibrations
Internal Methods
Calibration up to 225,000 lbf

Certification to Highest Standards and Traceability

The Instron Difference

Instron not only meets internationally accepted force calibration standards, but we routinely exceed them. All our calibration certificates provide comprehensive uncertainty of measurement data meeting the demanding needs of testing laboratories requiring full compliance to ISO/IEC 17025. Our calibrations usually cover a much wider force range than other calibration providers so that you can use your system confidently down to lower forces.

High-Capacity Deadweight Stack

The largest deadweight stack in North America outside of the National Institute of Standards and Technology (NIST) is maintained at Instron's corporate headquarters. This allows us to directly calibrate our field working standards to high accuracy levels.

Equipment Calibrated

Materials testing machines and instruments of all types, production equipment with force or weight transducers, hardness, structural testing rigs, simulators, mechanical, electromechanical or hydraulic drives.

Equipment Brands

Instron, Satec™, Dynatup®, Wilson® Instruments, Wolper™, Schenk®, MTS®, Instron IST, Tinius Olsen, Zwick, United, Lloyds Instruments, Mayes, Dennison, Shimadzu®, Rhiele, Baldwin®, ATS, and more.

Force Verification Standards

There are two internationally recognized standard methods for verifying the force measuring capability of a materials testing machine or instrument. One is published by American Society for Testing and Materials (ASTM) and is titled ASTM E4. The other is an ISO document, ISO7500-1. Both of these similar standards have been developed over many years, and are technically rigorous. If followed, they ensure that the force measuring system of your testing instrument is accurate under static or quasi-static conditions. ASTM E 4 specifies that the testing machine be accurate to 1% of reading over the verified range. This is very different from 1% of full-scale, which is how some suppliers spec their product. ISO 7500-1 defines several accuracy classes,ranging from 0.5 to 3. Most materials testing machines are calibrated to Class 1, which is equivalent to the ASTM E 4 requirement of 1.0%.

Which Force Verification Standard Should Be Used?

For the majority of customers, verifying equipment to either of the major standards (ISO7500-1 or ASTM E 4) is a low-risk way to assure that the calibration of force transducers is done properly, and the probability that the instrument will provide bad data is minimal. These standards provide a reasonable balance between the difficulty (and cost) of performing the verification and the quality of the results. Accepted practice is to verify systems in North America to ASTM E4 and systems in Europe to ISO 7500-1. Other regions vary based on local requirements. Ultimately, the choice is yours and Instron can calibrate to either standard to meet your needs.