Specifications

3. OPERATION

RPTs is available. Though it may not be practical and generally is not

necessary, the best possible reference with which to run AutoZ in absolute

measurement mode is a gas operated piston gauge (such as a DHI PG7601)

applying an absolute pressure near atmospheric pressure to the molbox

RFM test port. The best day to day reference is a properly calibrated DHI

RPM4 with a BA100K RPT interfaced directly as an external device to the

molbox RFM COM2 port.

• Allow the molbox RFM to stabilize at atmospheric pressure and ambient

temperature for 10 to 15 minutes before running AutoZ.

If AutoZ is on, the AutoZ value will be applied while running the calibration of

molbox RPTs and an AutoZ indication is included in the run calibration screen

(See Section 5.2.4.1).

 OPERATION

To access the molbox RFM AutoZ function press [TARE], <4AutoZ>. The

display is:

1. Active RPT designator.

2. Indication of whether AutoZ is currently ON or

OFF for this RPT and measurement mode.

1off 2view

3edit 4run ON

• Select <1off> (or <1on>) to change the AutoZ status.

• Select <2view> to view the current values of P

offset

for the two RPTs.

offset

should be zero when the molbox RFM is new or has just been calibrated.

• Select <3edit> to edit the values of Poffset.

The value of P

offset

is always displayed and entered in Pascal (Pa).

• Select <4run> to run the AutoZ routine which determines and activates P

offset

values by measurement of P

std,0

(see Section 3.4.4.4.2).

3.4.4.4.1 Edit AutoZ

The edit AutoZ function should be used with great caution as entering

inappropriate values and turning ON AutoZ may result in out of tolerance

measurements. In normal operation, the value of the AutoZ offset, P

offset

should be changed using the run AutoZ function (see Section 3.4.4.4.2).

Before editing P

offset

, (see Section 3.4.4.4, PRINCIPLE).