TB 9-6625-157-40
10. Ambient Pressure
a. Performance Check
(1) Place the pneumatic pressure standard in close proximity to the TI.
Allow
sufficient time for stabilization.
(2) Set the pneumatic pressure standard to display absolute pressure in kPa.
(3) Read ATMP (current measurement of the atmospheric pressure sensor) by
pressing TI keys as listed in (a) through (d) below.
(a) [SPECIAL]
(b) <7cal>
(c) <1atmP>
(d) <1view>
(4) TI will display the output in the format shown in figure 3.
Current measurement of
Indication that this is
the Atmospheric
an Atmospheric
Pressure Sensor
Pressure Display
100.0031 kPa
atmP
PA 101
Pa
PM
0.99999
Current value of the
Current value of the
Pressure Adder
Pressure Multiplier
(PA)
(PM)
Figure 3: Atmospheric Pressure Sensor Display.
(5) Compare TI ATMP indication to pneumatic pressure standard indication. TI
and pneumatic pressure standard will agree within 0.140 kPa. If not, perform b below.
b. Adjustments
(1) Calculate and record the difference between TI ATMP indication and pneumatic
pressure standard using formula below:
Pneumatic pressure standard [kPa] ATMP [kPa] = ĆatmP [kPa]
(2) Convert ĆatmP [kPa] from kPa to Pa by multiplying result above by 1000.
(3) Record the current value of the PA (Pressure Adder) from the TI display (fig. 3).
(4) Calculate the New PA by algebraically adding the ĆatmP to the Current PA:
Current PA [Pa] +ĆatmP [Pa] = New PA [Pa]
