Micromeritics ACCUPYC II 1345 Series Installation Instructions And Checklist page 27

Operate the TEC Module
When the TEC controller shows the correct temperature, there may be a small difference between
the temperature on the TEC unit and the AccuPyc display because two different sensors are being
used. The AccuPyc sensor and electronics are calibrated together to compensate for any
component differences between the sensor and the circuit board components. Micromeritics
considers the AccuPyc temperature display to be a more accurate reflection of the sample
temperature than the reading from the controller. The controller and the sensor used with the
controller cannot be calibrated.
The TEC controller may be adjusted to compensate for the small difference. If the AccuPyc
temperature is a little high, then reduce the setpoint of the TEC controller by the difference. Wait for
stabilization. Re-adjustment may need to be repeated until the correct AccuPyc temperature is
achieved.
The AccuPyc volume must be calibrated at the analysis temperature. Perform the volume calibration
in the normal way until it is time to insert the reference volume (sphere or spheres). After installing
the reference volume, wait at least 20 minutes to allow the reference volume to achieve the same
temperature as the AccuPyc. Then continue as normal.
When it is necessary to perform AccuPyc tests at a different temperature, re-calibrate the system
volume at the new temperature.
Volume Change with Temperature for the 10 cm
The reference spheres supplied with the 10 cm
were measured at 20 °C. The spheres will change volume with temperature. The change is very
small and is shown in the following table. Every sphere is a slightly different size, and so the table
provides the factor to be used if the value used during calibration needs to be adjusted. Multiply the
volume provided with the reference spheres by the value in the right column.
Temperature (°C)
15
20
25
30
35
For example, if the ball is 6.37182 cm
the table.
3
6.37182 cm x 1.00053 = 6.37520 cm
AccuPyc II 1345 Installation Instructions and Checklist
134-42875-02 (Rev A) — Jan 2021
3
AccuPyc
3
AccuPyc are made from tungsten carbide. They
Typical Volume
3
(cm ), two balls
6.37125
6.37182
6.37238
6.37295
6.37351
3
at 20 °C but run at 50 °C, multiply the Volume × the factor in
3
TEC Module
Factor
0.99991
1.00000
1.00009
1.00018
1.00027
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