BARTINGTON INSTRUMENTS
Page 24 of 82 OM0408/49
For standard 10cc samples the calibration sample, stored in the top of the sensor, should be
used as a reference to find the centre point. While taking continuous measurements of the
calibration sample, adjust the nylon screw with the non-magnetic adjuster tool, also located in
the top of the sensor, until a maximum value is obtained.
For non standard sample volumes, the sample being tested should be used as a reference, and
the height adjusted to achieve the maximum value.
The maximum adjustment of the height of the platen is ±10mm. For further information and
illustrations see
Appendix 4. Adjusting the MS2B Platen Height
.
6.4.2. Calibration Check
A calibration sample is provided which contains a type B2 ferrite specimen located at the centre
of an acetal cylinder. The sample is located in the top of the sensor, this can be removed and
placed in the sample cavity for checking.
Note:
The calibration sample can sometimes be difficult to remove.
The magnetic susceptibility value is marked on the sample. This material exhibits a negligible
frequency dependency, and may be used to check the sensor accuracy periodically.
Note:
The sample should not be exposed to high magnetic fields or demagnetising fields.
6.4.3. HF/LF Cross Calibration
The high frequency HF calibration can be adjusted relative to the low frequency LF calibration to
within 0.05% as follows.
1. Select LF, set zero, and check the calibration sample on this range.
2. Switch to HF, wait 10 seconds, set zero, and then measure the calibration sample again.
If the HF value is greater or less than the LF value by more than 0.05% then the error can be
removed by adjusting the HF trimmer control through the hole in the panel located in the top of
the sensor, using the non-magnetic screwdriver. Clockwise rotation will increase the HF scaling,
and counter clockwise decrease it. Perform a complete Z and M sequence following each
adjustment. The maximum adjustment range is ± 0.13%.
Note:
Although unlikely to change, it is advisable to carry out these quick checks before
any set of measurements.
