Druck DPI 530, User Manual

Page: 41 / 45

K162 Issue No. 2
DPI 530 User Manual 35
5 Maintenance
There is no routine maintenance on this instrument.
5.1 Fault Finding
Carry out the following general fault location routines in Table 5.1.
5.2 Controller Adjustment
This procedure should only be carried out after a leak check (section 5.3)
and when the instrument's outlet pressure becomes unstable or there is too
much noise or unusual noise from the controller valves. The instrument
must be disassembled as described in the calibration procedure.
Equipment
Digital voltmeter (DVM) 0.05% FS accuracy
Source pressure 120% FS
Preparation
1. Turn the set-point adjuster to the fully counter-clockwise position.
2. Select the instrument to measure mode.
3. Make sure that there is no pressure at the outlet connections and fit
blanks to both connections.
4. Connect the DVM +ve to TP VSUM and -ve to 0V.
5. Connect source pressure and the power supply.
Procedure (Figure 4-2)
1. Switch the instrument on and turn potentiometer RV17 to the fully
counter-clockwise position.
2. Select to position B links LK1 and LK3.
3. Carefully adjust potentiometer RV12 for a DVM reading of 0V ±0.1V.
Note: In this system there is high gain with a slow time constant.
4. Check that the Ready LED comes on.