palintest Green Drop Kit Instructions Manual page 18

4.1.8 Cleaning the Optics
Any build-up of dirt or deposits may interrupt light
transmission and affect readings.
To clean the optics, undo the two screws to remove
the optics base plate. Gently clean the internal
surfaces of the optics with a soft, non-abrasive
cloth. Deposits may be removed with a slightly
dampened cotton bud. Replace the optics base
plate and re-fasten the screws.
The photometer is fitted with long-life light sources
and contains no user-serviceable components.
If the instrument requires servicing or repair, this
can be arranged through our Technical Services
Department.
4.1.9 Replacing the Batteries
The battery compartment in the base of the
instrument is secured by four screws. To replace
the batteries, remove the cover and install the
batteries, observing the correct polarity as
indicated. Use 3 x 1.5V 'AA' alkaline batteries or
equivalent.
To avoid corrosion damage through leakage,
remove batteries from the instrument if it is to be
stored or left unused for a long period of time.