MAN-100 Weighing Equipment – Checking and Calibration

Care is to be taken when lifting calibration weights and equipment.

Equipment is not to be placed in locations where heat, vibration and/or air velocity issues exist.

1. Equipment to be Checked

Two forms of calibration checks are carried out, namely;

Primary calibration – every item, once a year to ASTM (American Standard Testing Method) standards.

Secondary calibration – selected items, daily and/or monthly checks as dictated by Batch Documentation or procedures to standard weights.

1.1.             Primary Calibration

All weighing equipment is checked against ASTM certified weights once a year by an Independent Calibration Group. They are tracked according to Plant Maintenance schedule and are split into different departments.

1.2.             Secondary Calibration

Selected equipment is checked daily to standard weights as dictated by Batch Documentation or procedures.  The standard weights are checked against the item that has itself been checked to ASTM standards.  These checks are logged in a logbook or as part of Batch Documentation.

2. Procedure

2.1.             Annual checks

The procedures for all balances, scales, check-weighers and load cells are in the form of a periodic maintenance task in the Plant Maintenance schedule.  A generic work instruction outlines the procedure to be performed.  (See SOP LAB-010)

2.2.             Daily Checks

Where daily checking of weighing equipment is required, it is to be done before the weighing of any raw materials or components.  The checking is to be done by the person working in the appropriate Process Team or Laboratory.  Every person using the equipment for the first time that day must ensure that the checks have been completed.

2.2.1.       Laboratory Equipment

Analytical Laboratory balances/scales are covered by individual procedure and manuals and employ the self-test method for secondary calibration, with the results logged in their relevant log books.

2.2.2.       Tablet Plant

The Tablet Plant enters the weight value into the logbook created for each balance. Use Balance calibration logbook form.

2.2.3.       Every time a balance/scale is checked to the corresponding check weights the value is recorded in the Batch Documentation or log book prior to use.

2.2.4.       In the case of any deviation from the standard, notify your Area Manager.  It is critical that all balances function properly.  The balance cannot be used until it has been repaired, re-calibrated and passed.  The Area Manager will arrange to have the balance serviced.

2.3.3.        It should be emphasised that the daily checks do not obviate the need to check correct operation of the balance each time weighing is carried out.  A satisfactory way of carrying this out is to check the balance for free swing at the TARE and LOADED position.

3. New Equipment

The Calibration Coordinator is to be informed of the installation of any new balance, scale, check-weigher or load cell.  This is to ensure that they are entered into the Maintenance System for regular calibration.

4. Summary of Changes