WIKA CPH6600 - Handbuch (Seite 29)

29 WIKA operating instructions, model CPH6600
14005103.03 11/2012 GB/D
GB
6. Commissioning, operation
6.7 Basic Setup and initial pressure generation
1. The CPH6600 is supplied with a special low-volume calibration hose to enable
faster pressure generation and quick pressure stabilisation. Included in delivery are
"Quick-fit" hose connectors and various adapters. It is recommended that this hose
is used in order to achieve the best results. As soon as the fittings are installed and
the calibrator is connected to the test item the calibrator is ready for use. Figure 5 in
chapter 6.13.2 "Calibrating a pressure-to-current transmitter" shows a typical setting.
2. The pressure calibrator must be configured for the appropriate application (see
chapter 6).
3. Set the pressure/vacuum selection knob to the desired function (+ for pressure and -
for vacuum).
4. Close the vent knob.
5. Press the pump key and monitor the pressure rise (or vacuum generation) until you
reach the desired pressure.
On the electric pump version the motor speed will start slowly while the
pressure is low (< 1 bar) to enable better control at low pressures.
6. The fine pressure adjustment enables the pressure to be set precisely.
7. To reduce or bleed off the pressure entirely slowly rotate the vent knob to the open
position. The pressure reduction is best controlled if this step is carried out carefully
and it makes reading the pressure easier.
6.7.1 Electrical pump
The CPH6600 incorporate a small, lightweight, battery-powered pneumatic pump that
enables the user to build a relatively high pressure of up to 20 bar, quickly and with
good control. Since this pump has an upper limit of 21 bar, there may be atmospheric
conditions where the full pressure of 20 bar cannot be achieved. High altitudes (around
3,000 ft. or 1,000 metres) or operation in cold temperatures could limit the pump to
19 bar. In these cases, the fine pressure adjustment can be used to generate additional
pressure, should the full range be required.
In these situations the user should begin the calibration with the fine pressure
adjustment knob in the full anti-clockwise position and then, when the electric pump
reaches its limit, turn the fine pressure adjustment knob in the clockwise direction to
raise the pressure and to set the desired value.