Memmert PM 200/400/500 Pump Module (Generation 2003) - Manual (Page 40)

VO page 40
24.2 Calibration-pressure (vacuum)
User-calibration of the oven on the controller at three user-selected vacuum values:
CAL1 pressure calibration at low vacuum pressure
CAL2 pressure calibration at medium vacuum pressure
CAL3 pressure calibration at high vacuum pressure
A positive or a negative calibration correction can be applied to each selected calibration point.
General calibration instructions:
1. Select the required calibration vacuum in SETUP and set the corresponding calibration correction
to 0mb.
2.
Using a standard vacuum gauge, measure the deviation at the selected calibration vacuum under
steady conditions.
3.
Set the calibration correction in SETUP. If the measured vacuum pressure is too low, the calibration
correction has to be set with a negative sign.
4. Carry out a check measurement with the reference gauge.
5. The procedure can be performed for up to 3 calibration vacuum pressures.
Example: to correct the vacuum deviation in the load at 500 mbar.
1. Set calibration vacuum CAL2 in SETUP to 500mb and set the corresponding calibration
correction to
0
mb.
2. In normal operation and at the vacuum setting of 500 mbar, an actual vacuum pressure
of 497 mbar is measured using a reference gauge.
3. Set calibration correction CAL2 in SETUP to –3mb.
4. After the oven has stabilised, the reference gauge should indicated 500 mbar.
5. A further vacuum calibration below CAL2 can be programmed with CAL1, and another one above
CAL2
with CAL3.