4.6 FREQUENCY OF CALIBRATION
It is necessary to periodically re-calibrate to the set piece (see chapter 5) and
experience will indicate an appropriate frequency. As re-calibration only
takes a matter of seconds it is often decided to check calibration before each
batch of measurements.
4.7 TAKING READINGS
All readings are taken in MEASURE mode which is always entered when
either SET-UP or CALIBRATE modes are exited by pressing
END.
To take a reading first select the correct lacquer number for the sample being
measured by using the arrow keys or by pressing
LACQUER NUMBER
followed by a 1 or 2 digit number and the
ENTER
key.
The selected lacquer number will be displayed which of course must have
been previously set-up and calibrated to the set piece (known sample) as
described above. With the probe correctly in position the film weight will be
indicated on the display.
4.8 READING FAULTS
If the FAULT indicator illuminates or the display reads "Poor" then a pinhole
or missing lacquer exists on the sample currently being measured.
If the reading is significantly different to the expected value, check the
following;
A)
The probe crocodile clip is making good electrical contact with
the metallic substrate of the sample.
B)
The probe tip is being used correctly i.e. square to the sample with the
correct pressure applied.
C)
The probe tip is clean and undamaged.
D)
Probe connections are OK and the operators hands are not in
contact with the probe conductor.
If these points are OK then check the calibration by measuring the set piece
(known sample) and if significantly different re-calibrate the channel (section
4.5) and if necessary re-calibrate the probe (section 2.13).
Whilst a valid reading is not being obtained from the sample the display will
show "void". If no reading can be obtained by placing the probe on the
sample then check items A to D above.
Summary of Contents for SI9500
Page 11: ...OPERATION KEYS NUMERIC KEYPAD ...