Specifications
Channel Master Operation Manual
page 26 RD Instruments
8.4.3 Pressure Sensor Calibration and Close-up
a. Interconnect and apply power to the Channel Master as described in
“Setup the Channel Master,” page 10.
b. Start the BBTalk program (for help on using BBTalk, see the RDI Tools
User’s Guide).
c. On the File menu, click Break (you can also press the End key to send
a break or use the Toolbar and press the B button). You should see the
wakeup message appear on the log file window.
d. Leave the Channel Master powered up in a temperature-controlled area
for at least one hour so that any temperature gradients within the system
equalize.
e. At the > prompt, type #sc. The Channel Master will respond with:
>#sc
*** CAUTION: These commands are reserved for RDI use
and may not be currently supported!
Input local barometric pressure in inches of mercury:
f. Determine the barometric pressure at your location as accurately as pos-
sible.
For example, an airport weather forecasting service in the United States
may say “altimeter 2984”… The numbers represent barometric pressure
in hundredths of inches of mercury. Divide this number by 100 so that it
represents barometric pressure in inches of mercury (e.g., 29.84inHg).
International users may be given the barometric pressure in millibars
(mb) or hectopascals (hPa). The barometric pressure must be entered in
inches of mercury (inHg). To convert between inches of mercury
(inHg) and millibars (mb) or hectopascals (hPa), use the formula
P
inHg
= 0.0295300 x P
mb
.
For example, to convert 1013hPa to inches of mercury (inHg), multiply
1013 x 0.0295300 so that it represents barometric pressure in inches of
mercury (e.g., 29.92inHg).
g. Enter this number in inches of mercury (inHg) at the prompt and press
enter.
h. The Channel Master should respond with:
“Make sure the unit is open to ambient pressure. Hit any key to con-
tinue...”.
i. Press any key to continue.
j. The Channel Master should respond with the following message.
“Now close the unit and tighten the closeup hardware. After this, hit any
key to continue...”.