Fluke RUSKA 7252, Руководство пользователя

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Installation
Observing the Calibrator’s Full Scale Rating
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Observing the Calibrator’s Full Scale Rating
The full scale pressure range of each channel of the Calibrator is noted on a label on the
front panel of the instrument. The label denotes the pressure range for channel A and for
channel B.
Pneumatic Connections
The following sections discuss each port. All ports are 1/4 inch NPT pipe fittings.
See Figure 3-1. Remove all plastic shipping plugs from the back panel pneumatic ports.
Pressure Supply Port
Each channel has its own individual pressure supply port which must be connected to an
independently regulated source of clean, dry nitrogen or air. Shop air should not be used.
Refer to Appendix A for supply port gas purity and pressure regulation requirements.
W
Warning
Make sure that you connect the proper pressure supply to the
correct pressure channel. The pressure range for each channel
is identified on the front panel of the RUSKA 7252. This is
depicted using the letter A and B for the two channels and the
pressure associated with these ranges. On the rear of the
instrument, there are two manifolds, one for channel A and one
for channel B. Verify that the pressure supply is regulated to
the proper pressure based on the actual full scale pressure
range of each channel.
Tubing must be of at least 1/8 inch (3 mm) inside diameter and
of a sufficient wall thickness for the pressure. Either stainless
steel or copper tubing is acceptable.
Exhaust Port
The exhaust port may be left open to atmosphere under most conditions. A vacuum pump
is required in Absolute mode for controlling pressure below atmospheric pressure, and
will allow lower pressure control in Gauge mode (i.e. to control to 0 psig). Supply
vacuum lines must have minimum restrictions. Tubing should have a minimum I.D. of
1/4 inch. In small rooms, the exhaust port should be piped outside to prevent an
accumulation of nitrogen. It is also very important to install an auto-vent valve to the
vacuum pump. The purpose of the valve is to vent the vacuum to atmosphere when the
pump is turned off.
The addition of tubing to direct discharged gas out of the work area will also significantly
reduce audible noise. It is acceptable to add tubing to the exhaust port for the primary
purpose of reducing noise. Care should be used to prevent blockage of the exhaust tube.
If the exhaust tube is significantly restricted, then the exhaust tube can be exposed to full
scale pressures.
Absolute Models
When the Calibrator is a permanent absolute system, the Exhaust port and Reference port
should be externally connected together to allow the system to function with a single
vacuum pump. Using 1/4 inch NPT fittings, connect tubing with a minimum I.D. of
1/4 inch to the Exhaust port and the Reference port. Larger I.D. pressure line is
recommended if available. Using appropriate pneumatic fittings, connect the other end of
the tubing to the vacuum supply line(s). This allows the system to function with a single
vacuum pump. The system will use the vacuum source for control or zeroing, as required.