11.
Calibration Check
Check at the 5 g position
6. Repeat the process as described in 4. and 5. above, but using the 5 mark on the scale
and a setting one-and-a-half lines width above and then below the 5 mark and with the 5 g
weight on the prism cone. The actual point of balance can again be found if required.
Note:
The tolerances in the zero, 2 g and 5 g tests above represent ±0.05, ±0.05 and
±0.075g respectively. If the tonometer is found to be outside the stated limits it should be
returned to your supplier for attention.
12.
Storage of Prism and Tonometer
The doubling prism must always be removed from the tonometer, cleaned following the
cleaning instructions supplied with the prisms and inserted, cone downward, into the hole in
the foam interior of the carrying case (Fig 14, 3). The tonometer should then be returned to
the carrying case.
Do not pack the Perkins tonometer with the prism still in the instrument.
Never store the instrument with the spring under load - i.e. return the milled thumb-wheel
to below zero.
The suppliers cannot accept responsibility for the performance, reliability or safety of this
equipment if it is used, serviced or modified by unauthorized persons.
Exterior cleaning of the tonometer body should be carried out using an antiseptic wipe, a
cloth moistened in a mild soap solution or with 70% isopropyl alcohol.
Solutions containing alcohol, benzene etc., should not be used.
Note
Repairs
In the event of damage do not attempt local repairs but return the tonometer in its case,
carefully packed, to your manufacturer for attention.
Warranty
Unauthorized attempts at repair will immediately nullify the warranty.
- continued
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