Standardized procedures for cleaning laboratory balances

Scope: Benchtop Balances This SOP describes the procedures for cleaning laboratory (benchtop) balances (analytical and precision balances). Designed to guide laboratory workers in thoroughly cleaning their balances. The cleanliness of a laboratory balance can greatly affect operating efficiency and balance life, as well as user safety.

Cleaning Rules – Code of Conduct 1. Ensure that relevant personnel are provided with instructions for cleaning the balance. Improper handling may result in damage to the weighing system or electronic components. 2. Wipe off powder and dust first, then sticky substances. 3. Wipe off powder and dust with paper towels. Do not purge; this may cause dust or sample material to fly from the balance. 4. When removing sticky substances, use a lint-free soft cloth and a mild solvent (isopropyl alcohol or ethanol 70%); avoid abrasive materials. 5. Do not spray liquid directly on the balance. 6. When using a cloth or brush, wipe from the tapered opening (where the scale pan is located) or the air duct (the gap between the front and rear of the windshield). 7. Remove parts for cleaning as much as possible (such as scale pan, water tray, tray, etc.). Only remove parts that can be removed without tools and are described in the operating instructions. 8. If possible, do not disconnect peripheral devices unless necessary. 9. Clean the balance at the work location; do not tilt, move or carry the balance without instructions on how to carry it. Improper handling can cause costly damage.

Cleaning Frequency Recommended cleaning frequencies vary depending on the industry, application, and frequency of instrument use. In general, Mettler Toledo recommends cleaning your balance immediately after each use or after changing samples. When handling potentially toxic substances, the balance must be cleaned after each use.

Cleaning steps The following steps describe the general cleaning procedures that apply to all bench balances. Depending on the type and model of the balance, not all the steps mentioned may apply (e.g. 0.1 g precision balances do not have draft shields or rings).