DeFelsko PosiTector 200 v.1.2 - Manual (Page 14)

Page 14
Adjustment
Adjustment, or Calibration Adjustment, is the act of aligning the Gage's thickness
readings to match that of a known reference sample in order to improve the
accuracy of the gage on a specific coating. (pg.7)
The PosiTector 200 is factory calibrated. But in order for it to take accurate
thickness measurements of a particular material it might be necessary to adjust the
gage for that material. To determine if an adjustment is necessary for your
application, measure a sample of known thickness of the coating material to be
measured. If the average of a series of measurements is not close to the expected
thickness, adjust to the expected thickness. Samples should be flat, smooth and
as thick or thicker than the maximum expected thickness of the piece to be tested.
During the work shift, if the Gage is dropped or suspected of giving erroneous
readings, its accuracy should be re-verified.
In the event of physical damage, wear, high usage, or after an established
calibration interval, the Gage should be returned to the manufacturer for repair or
calibration.
Temperature variations change the sound velocity of materials and transducer
delay tips. Thus verification of accuracy should be performed with the reference
standard, materials to be tested, and the Gage at the same temperature.