Specifications
PCA
4.4 Differential Pressure Measurement
Operation
The difference in pressure (
P) between two areas can be measured by
using the PCA’s two pressure ports and DRAFT Screen. By using Pres-
sure
Port
2 (–)
as the reference, the pressure applied to
Port
1 (+)
will be
displayed on the DRAFT Screen as the differential pressure between the
two ports.
1.
Turn on the analyzer by pressing the
ON/OFF
k
e
y; wait for the warm-up
cycle to complete; then press the
MENU
key until the first DRAFT
Screen is displayed (refer to Section 4.9).
If a TA-SENSOR ERROR is
displayed, as the result of the probe’s thermocouple not being plugged
into the analyzer, press the
RUN
key
to acknowledge the error before
pressing the
MENU
key
.
2.
While the first DRAFT Screen is displayed, remove any hoses con-
nected to Pressure Ports 1 and 2; then press the
ENTER
key to zero
these ports to atmospheric pressure.
3.
Connect two sampling hoses to Pressure Ports 1 and 2 (Figure 4-3).
Then place the open end of each hose into the areas being measured.
4.
The differential pressure between
the two areas is now displayed on
the third DRAFT Screen. If the
pressure at Port 1 is higher than
Port
2, then the pressure differ-
ence will be
positive
. But if the
DRAFT
DRAFT
–
0.95 WC
HOT SPOT ---- °C P
«
S
pressure at Port
#1 is lower, then the pressure difference will be
negative
. The reading shown in this example indicates that the
pressure at Port
1 is 0.95" H
2
O
lower
than the pressure at Port
2.
Sampling Hoses with quick-
connect fittings are available
as an optional accessory.
Refer to Section 8.2.
Pressure Port 1(+)
Pressure Port 2(–)
Reference
Figure 4-3. Differential Pressure Hose Connections
Instruction 0024-9219
4-7