Yokogawa AC8 Calibration Units - Manual (Page 7)

7
IM 11M6D2-02E-A
For setting on fall, apply pressure equal to normal system
operating pressure. Reduce source pressure to set point
value. Turn the adjustment clockwise until switch “clicks”
[circuit across N.C. (black) and COM (white) closes]. For
setting on rise, apply desired pressure and turn adjustment
left until switch “clicks” [circuit across N.O. (red) and COM
(white) terminal closes].
5. After completing adjustments, slide the cover closed over
the adjustment compartment. Recheck the set point value.
6. Wire the pressure switch Normally Open to the AC4/AC8
terminals at the calibration unit that are labeled PS. Remove
the jumper across the PS terminals.
V. INITIAL FLOW RATE SETUP
5.1 CHECKING FOR LEAKS
Before considering your calibration unit operational, it is a
good idea to check for leaks along the full distance of the cal
line tubing. Additionally, perform a cal check to confirm that
the gases are plumbed correctly to each probe.
1. Plug all the cal and reference air lines at the probes. This
requires disconnecting the fitting at the ZR22 Probe and
plugging the tubing.
2. Set the flow rate of the Zero Gas and Instrument Air to 20
psig using the regulators.
3. Locate the block solenoid shown in Figure 5. Using a flat
tip screwdriver, turn the manual override screw on the block
solenoid to the 90º position as shown in Figure 5.2.
4. Turn the channel solenoid valve’s manual override screw
to the horizontal, or ON (NOT NORMAL) position for Uall
probes in use. See Figure 5.1 and 5.3.
5. Apply leak detection spray on all compression fittings and
bends of the cal line tubing for all probes. Spray both the
reference air and cal gas line(s).
6. Inspect the full length of the cal lines to determine if there
is a leak. Repair any leaks.
7. After repairing the leaks, if any, turn all probe channel
solenoids and the block solenoid to the NORMAL position as
shown in Figure 5.2 and 5.3.
8. Unplug tubing at the ZR22 probe(s) and reconnect.
5.2 SETTING REFERENCE AIR FLOW
Locate the reference flow air meters in Figure 5.1. Adjust the
black flow adjustment knob on each reference air flow meter
to 0.8 LPM (800cc/min).
NOTE
Reference air flow should be adjusted before the calibration
adjustments are made.
CH ANNE L MA NIFOLD
WIT H MANU AL
OVE RRIDE AN D
FLOW ADJU STE R
M1133BY (4 Channel)
M1133BZ (8 C hannel)
Figure 5.1 AC8 Parts Listing