QUANTACHROME INSTRUMENTS MVP-6DC - Calibration; Recalibration

V. CALIBRATION
Page 6 of this manual contains calibration information for reference during calibration and analysis
calculations. Print that page and enter the values as indicated on the Calibration Tag or Printout
provided with your instrument. This includes the sample cell volumes (V
C
), the reference volumes
(V
R
), the volume of the large calibration sphere (V
cal
large) and the volume of the micro calibration
spheres (V
cal
micro) provided with the MULTIPYCNOMETER. If, for any reason it is suspected that
the value of V
C
or V
R
has been altered then recalibration should be performed. Powder blowing out
of the sample cell into the tubing or operation at temperatures substantially different that room
temperature will require recalibration.
Recalibration
To calibrate the MULTIPYCNOMETER the following steps should be followed in order:
1. Place the large calibration sphere into the large cell. Insert the large cell into the cell holder,
replace and secure the cap.
2. Open toggle valves I and II.
3. Turn the selector valve to "CELL".
4. Open the "VENT" toggle and "RATE" valves.
5. Open the “GAS FLOW IN” toggle valve and adjust its "RATE" valve until the display
shows about 1 (psig).
6. Purge the MULTIPYCNOMETER" in this mode for about 5 minutes.
7. Close the “GAS FLOW IN” toggle valve.
8. When the display shows a stable reading, set it to 0 using the zero knob and turn the selector
valve to "REF".
9. Close the "VENT" toggle valve.
10. Open the “GAS FLOW IN” toggle valve until the pressure is approximately 17 (psi), then
close the “GAS FLOW IN” toggle valve.
11. When the display is stable, note the pressure reading (P
1
).
12. Turn the selector valve to "CELL".
13. When the display is again stable, note the new pressure reading (P
2
).
14. Vent the reference volume and sample cell holder (V
R
+ V
C
) by opening the "VENT" toggle
valve.
15. Remove the calibration sphere from the large cell and repeat steps 1-14 noting the pressures
P
1
′, P
2
′ with the selector valve in "REF" and "CELL" positions respectively.