Page 104 - The Veterinary Laboratory and Field Manual 3rd Edition

The selection, use, maintenance and quality control of laboratory equipment and supplies 73

Always indicate (on a label) the due date of the maintenance contracts are stored with the qual-
half yearly control on the balance. ity manager. The maintenance company should
If the limit value is exceeded, take the fol- be accredited and should have an ISO 9001 cer-
lowing steps. tificate.
During the yearly maintenance, the following
• Check if the balance is completely level and tasks are performed:
if all weight measurements are properly per-
formed. • thorough cleaning of the balance
• If there is still a problem, use a different certi- • calibrating the balance with certified calibra-
fied control weight. tion weights
• If still a problem, contact the manufacturer of • checking the accuracy, precision, linearity and
the certified control weights. eccentric weighing.
• If the limit values are exceeded, the pos-
sible consequences on earlier weight After the maintenance, a calibration report and
measurements should be considered. All certificate are delivered.
measurements after the last successful refer- The yearly maintenance is registered on
ence control weight measurement and before the form ‘FORM-SOP-LABORATORY-EQUIP-
the exceeded measurement should be traced. 01–03-Balance maintenance by maintenance
Possible consequences on those laboratory company’. It is good practice to label each bal-
results should be examined and rectified. ance with the date of the yearly maintenance.
• The investigation of the problem and all
corrective actions are registered on ‘FORM-
SOP-LABORATORY-EQUIP-01–02-Corrective Water baths
actions’.
Water baths (Figure 2.37) are used to maintain
yEarLy SErvIcInG the temperature of liquids held in laboratory
If possible, the laboratory should have a con- containers. The temperature range used for most
tract for a yearly servicing on each balance. The purposes is 37°C to 60°C. There is a wide range of

Figure 2.37 Water bath.
Photo: Willy Schauwers, Provincial
Institute for Hygiene, Antwerp,
Belgium.

Vet Lab.indb 73 26/03/2019 10:25