25
5.9.
MICRO SPHERE RUN
5.9.1. INSTALL TWO MICRO SPHERES, EACH WITH A VOLUME OF 1.0725 cc IN
THE CELL CUP. (THIS IS EQUIVALENT TO FILLING THE MICRO CUP WITH THE
SPHERE INDICATED AS THE SAMPLE.) PERFORM THE STEPS LISTED IN
SECTION 5.6.1. (THE PURGE ROUTINE) WITH THE SMALL CELL FILLED.
5.9.2. CLOSE
ALL THE TOGGLE VALVES.
5
.
9.3. TURN THE SELECTOR VALVE ON THE FRONT PANEL TO THE CELL
POSITION
AND THEN OPEN THE
GAS OUT TOGGLE VALVE.
5.9.4. TURN THE ZERO ADJUSTMENT KNOB ON THE FRONT PANEL UNTIL A
0.000 PSIG READING IS DISPLAYED ON THE DIGITAL PANEL METER
.
CLOSE THE
GAS OUT TOGGLE VALVE.
5.9.5. TURN THE SELECTOR VALVE TO THE REFERENCE
POSITION
AND
CLOSE THE GAS OUT TOGGLE VALVE.
5.9.6. OPEN THE GAS IN TOGGLE VALVE AND, WHEN THE DIGITAL PANEL
METER READS 17.0 PSIG, CLOSE THE GAS IN TOGGLE VALVE.
5.9.7. VERIFY THAT THE PRESSURE DISPLAYED ON THE DIGITAL PANEL
METER DOES NOT CHANGE DURING A 10-SECOND PERIOD. TAKE THE
P1
PRESSURE READING ON THE DIGITAL PANEL METER AND ENTER THAT
NUMBER ON THE MICRO SPHERE RUN DATA SHEET (APPENDIX C, ITEM C.1.4.).
.
5.9.8. TURN THE SELECTOR VALVE ON THE FRONT PANEL TO THE CELL
POSITION.
5.9.9. VERIFY THAT THE NEW PRESSURE DISPLAYED ON THE DIGITAL PANEL
METER DOES NOT CHANGE DURING A 10-SECOND PERIOD. TAKE THE
P2
PRESSURE READING ON THE DIGITAL PANEL METER AND ENTER THAT
NUMBER ON THE MICRO SPHERE RUN DATA SHEET (APPENDIX C, ITEM C.1.4.).
5.9.10. CALCULATE VP = VC - VR
×
((P1/P2) -1)
WITH NUMBERS FOR VC AND VR
TAKEN FROM THE CALIBRATION SECTION. VERIFY THAT THE CALCULATED
VALUES ARE WITHIN 0.5 % OF THE EXPECTED VOLUME OF 2.145 cc. THE UPPER
LIMIT IS 2.1557 cc AND THE LOWER LIMIT IS 2.1343 cc.