Yokogawa AC8 Calibration Units - Manual (Page 15)

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IM 11M06D03-01E-A
VII. SETUP PROCEDURES, AC1
Locate the reference air flow meters, and adjust the flow adjustment knobs as outlined below:
Reference Air: 0.8 LPM
Calibration Gas: 0.6 LPM
The maximum working pressure of the MC1 and AC1 unit is 35 psi. Excessive pressure can damage the Zirconia
cell of the ZR22G Oxygen Probe.
7.1 INITIAL FLOW RATE SETUP
Ensure that the calibration gas and reference air lines are properly plumbed to the left side of the AC1 Auto Cal Unit. The
zero gas and instrument air should be set at approximately 20 psi (± 2 psi). Power is not required to set the flow rates.
7.1.2 SETTING THE REFERENCE AIR FLOW RATES
Locate the reference flow meters. Adjust the flow adjustment knob on the REFERNCE AIR FLOW METER to 0.8 LPM
or 800ml/min.
7.1.3 BALANCING PRESSURE DROPS IN THE CALIBRATION LINES
For accurate calibrations, the auto cal system must provide a fixed flow of Zero gas and Span gas. To balance the
pressure drops perform the following steps:
1) Locate the BLOCK and SPAN GAS SOLENOID. Using a screwdriver, turn the override screw to the manual
position. See Figure 5.2
2) Use the flow regulator knob on the CAL GAS FLOW METER to adjust the flow to 1.0 LPM.
3) Switch the override screw of the SPAN GAS solenoid to AUTO.
4) Turn the override screw for the ZERO GAS solenoid to MANUAL.
5) Adjust the pressure regulator on the zero gas cylinder for a flow of 1.0 LPM on the Calibration Gas flow meter.
DO NOT USE the flow regulator knob of the flow meter to achieve this flow level.
6) Adjust the flow regulator knob on the Calibration Gas flow meter until the flow meter reads 0.6 LPM.
7) Verify that all the manual overrides are set back to AUTO.
7.2 STANDARD OPERATION
• The Reference Air Flow meter indicates 0.8 LPM during normal operation and calibration.
• All manual overrides are set to the AUTO position.
• The Calibration Gas flow meter will show a flow of 0.6 LPM during Calibration only.
Before considering your calibration unit automated, it is good practice to check for leaks along the full distance of
the calibration line tubing, in addition to performing a CAL CHECK to confirm that the gases are plumbed correctly
to each probe.
CAUTION
CAUTION