Page 22 - Feed Lab

Lab Equipments Maintenance & Handling Procedure Suguna Management System Ver 1.0 / SOP / FQL / P1 - 02 Page 2 of 6

Instrument Log Book: The main purpose of the usually located at the rear of the balance. Turn the
instrument log book is to provide a permanent record of leveling feet clockwise to raise the balance and
instrument performance and to be used as a basis for counter-clockwise to lower the balance. The balance
validating data and projecting repair and replacement cannot be moved and then used without a
needs, or new acquisitions. If applicable, the service readjustment or check of the level. Make sure the
contract number is recorded in the log book. balance pan is empty. Press the tare button; the output
should be either 0.0000 or 0.00000. Analytical
LABORATORY EQUIPMENTS HANDLING balances are capable of using their internal weights for
TECHNIQUES calibration. The reading will progress from C to CC.
Once it is finished, the reading will return to 0.0000. The
ANALYTICAL BALANCES
reading will display CC when the calibration is finished.
This document provides the procedures to calibrate, The Laboratory Analyst must return the knob to its
clean, weigh materials, and perform routine original (or middle) position before weighing; the display
maintenance on top-loading and analytical laboratory will again read 0.0000. See balance manual for
balances. instructions pertaining to other models. The limit
indicates the amount that the weight can deviate from
Cleaning: Cleaning is essential in everyday usage of
the balances to maintain quality assurance in the the certified amount.
laboratory since weighing is the most basic and yet one Typical limits are listed below: Top Loading Balance
of the most important steps in an analysis. it is Weight < 100 g ± 0.10 g ; > 100 g ± 0.50 g, Analytical
important to follow the proper methods carefully to Balance Weight ± 0.0005 g
obtain the most accurate results. Unplug the balance
before cleaning and do not use any harsh or abrasive Attention:
cleaning agents. Allow nothing to enter the balance's FNever exceed the stated maximum load of the
internal mechanism. Also handle the balance pan with
balances.
care, do not touch the balance pan feet on which it
rests or the place where the pan contacts the balance. FObjects to be weighed should be allowed to attain
The balance should be cleaned as necessary. For the temperature of the balance before weighing.
simple cleaning, such as removing sample from the FIf the object has been heated, sufficient time must
balance pan, a soft camel hair brush should be used.
be allowed for cooling. The time required to attain
Make certain no small particles remain on the balance
pan since even the smallest amount can affect a the temperature of the balance varies with the size,
reading or corrode the pan. To clean the weights use etc, of the object, but as a rule 30-40 minutes is
sufficient.
ethyl ether and a lint-free wipe. The ether should only
be used in a solvent hood. Wipe the weight until it is
COMMON ELECTRICAL EQUIPMETS
visually clean and no ether remains. The weights
should be cleaned as needed. Hot plate: The electrically heated hot plate is of great
value in the analytical laboratory. The heating elements
Calibration: A calibration that approximately spans the and the internal wiring should be totally enclosed; this
weighing range should be done using the traceable protects them from fumes or spilled liquids.
weight set. Before calibrating, make certain that the
balance is clean. Do not touch the weights directly with Electric Ovens: The most convenient type is an
your hands. Use a dust-free glove, tweezers or a lint- electrically heated, thermostatically controlled drying
free wipe to handle the weight (see cleaning protocol). oven having a temperature range from room
o
o
Make certain the doors are closed before calibration temperature to about 100 C to 200 C. The
o
and during weighing to prevent air currents from temperature can be controlled with + / - 1-2 C. They
affecting the readings. Check the leveling bubble to are used principally for drying precipitates or solids at
make sure the balance is level. If it is not, level the comparatively low controlled temperatures and have
balance by adjusting the balance feet. The level bulb is virtually superseded the steam oven.

Prepared by : Approved by :
12 Director - Technical