7-
43
PRES
sure
PRES=number
is used to inform the 5A-1MP of the barometric pressure (in
(factory default=
inches of mercury) of the environment being sample. The
29.92 in Hg)
pressure is required for accurate calculation of the relative
humidity and the dewpoint temperature. The number may be
entered in either standard or scientific notation. Changes may
be made permanent through the use of the
SAVE
command.
PRES?
returns the currently stored barometric pressure value used for
the calculation of relative humidity and dewpoint temperature. It
is returned in inches of mercury in 8 digit scientific notation.
IBM BASICA Example (assuming com1 is initialized to #1 and 5A-1MP
ECHO
is
OFF
):
.
.
.
100
INPUT "WHAT IS THE CURRENT BARO
'Get current pressure from operator.
PRESSURE", BP
110
PRINT #1, "PRES="; BP
'Send to 5A-1MP.
.
.
.
TERMINAL Example (assuming
ECHO
is
ON
):
PRES?
Get last pressure stored.
2.901
29.92 is power-up default value (sea level).
PRESsure=24.43
Set to 24.43 inches of mercury.
PRES?
Verify.
2.401
OK.
________________________________________________________________________
IEEE 488 Example (HP Rocky Mountain BASIC syntax):
.
.
.
100
INPUT "WHAT'S THE PRESSURE (PSIA)?"; P
!Determine pressure.
110
OUTPUT 705; "PRES = "; P*2.03602
!Tell 5A-1MP.
.
.
.
400
OUTPUT 705; "PRES?"
!Retrieve pressure setting.
410
ENTER 705; P
420
DISP "PRESSURE STORED AS "; P; " " "HG"
!Display in "Hg.
