TS–008 Repeatability test on weighing instruments
This policy prescribes the minimum load to be removed when performing a repeatability test on a weighing instrument.
NOTE
Test loads, as specified in Regulation 58 of the Weights and Measures Regulation 1999, do not have to be Working Standards for performing the repeatability test. Any stable substitution load may be used that falls with the specified load parameters.
Reference documents
- Weights and Measures Act 1987(external link)
- Weights and Measures Regulations 1999(external link)
- Regulation 58 - Repeatability
- Certificate of Approval Register
Policy
The following instructions detail the loads an Accredited Person must remove for each class of weighing instrument when performing a repeatability test and the minimum point of return between load applications:
- Class I & II remove 100% of load when performing a repeatability test as per Regulation 58 of the Regulations.
- Class III – The load required to be removed for repeatability tests and minimum return points between applications is specified in Table 1. The instrument can return to a lower value of ‘e’ if desired.
- Class IIII – The load required to be removed for repeatability tests and minimum return points between applications is specified in Table 2. The instrument can return to a lower value of ‘e’ if desired.
Table 1 – Class III
| Capacity of instrument under test | ± 10% of ½ max capacity | Max (90-100%) |
|---|---|---|
| 0 - 100 kg | Return to zero | Return to zero |
| 101 kg + | Return to 500e MPE point | Return to 2000e MPE point |
Table 2 – Class IIII
| Capacity of instrument under test | ± 10% of ½ max capacity | Max (90-100%) |
|---|---|---|
| 0 - 100 kg | Return to zero | Return to zero |
| 101 kg + | Return to 50e MPE point | Return to 200e MPE point |
NOTE
The maximum permissible errors for the repeatability tests are expressed as “absolute value”, this is different from other test points where the maximum permissible errors are expressed as positive or negative values.
Refer to Regulation 58 of the Regulations for the full wording and requirements.
Where the repeatability test cannot be performed in accordance with the requirements of Regulation 58 and this policy document, the approval certificate for the instrument should be followed.
A hopper or bin type weighing instrument when tested for repeatability may use a combination of unknown load + standard weights, and it is sufficient for the total value of standard weights to be removed and reapplied for the purpose of repeatability test.
Trade Measurement — Technical Policy
| Policy number: | TS - 008 |
|---|---|
| Effective date: | August 2016 |
| Version date: | March 2021 |
| Version number: | 3 |
| Policy name: | Repeatability test on weighing instruments |
| Reviewed by: | Davis White, Legal Metrology Advisor and Senior Trading Standards Officer |
| Approved by: | Phil Sorrell, Team Leader Compliance and Inspection |