Fluke 725 - Manual (Page 37)

Using Measure Mode
27
To avoid damaging the pressure module from
overpressure, never apply pressure above the
rated maximum printed on the pressure
module.
To avoid damaging the pressure module from
corrosion, use it only with specified
materials. Refer to the printing on the
pressure module or the pressure module
instruction sheet for the acceptable material
compatibility.
1. Connect a pressure module to the calibrator as
shown in Figure 13. The threads on the pressure
modules accept standard ¼ NPT pipe fittings. Use the
supplied ¼ NPT to ¼ ISO adapter if necessary.
2. Press
A
. The calibrator automatically senses
which pressure module is attached and sets its range
accordingly.
3. Zero the pressure module as described in the
module’s Instruction Sheet. Modules vary in zeroing
procedures depending on module type, but all require
pressing
K
.
If desired, continue pressing
A
to change pressure
display units to psi, mmHg, inHg, cmH
2
O@4
°
C,
cmH
2
O@20
°
C, inH
2
O@4
°
C, inH
2
O@20
°
C, mbar,
bar, kg/cm 2 , or kPa.
Zeroing with Absolute Pressure Modules
To zero, adjust the calibrator to read a known pressure.
This can be barometric pressure, if it is accurately known,
for all but the 700PA3 module. The maximum range of
700PA3 is 5 psi; therefore the reference pressure must be
applied with a vacuum pump. An accurate pressure
standard can also apply a pressure within range for any
absolute pressure module. To adjust the calibrator
reading, proceed as follows:
1. Press
K
, REF Adjust will appear to the right of the
pressure reading.
2. Use X to increase or W to decrease the calibrator
reading to equal the reference pressure.
3. Press K again to exit zeroing procedure.
The calibrator stores and automatically reuses the zero
offset correction for one absolute pressure module so that
the module is not rezeroed every time you use it.