Series 905
Page 29
Design Guide
Calibration and Adjustment Commands
Atmospheric Calibration – ATM
The ATM command sets full scale readout for the MicroPirani™. Vent the transducer to atmospheric
pressure before performing atmospheric calibration. Optionally, the user can manually vent to atmosphere,
as described in the section Venting to Atmosphere.
Values: Pressure value in scientific notation
Command:
@253ATM!7.60E+2;FF
Command Response:
@253ACK7.60E+2;FF
Gas Type Calibration – GT
The GT command sets gas type for measurement. The MicroPirani™ measures thermal conductivity; using
the gas calibration compensates for gas errors.
Values:
NITROGEN
,
AIR
,
ARGON
,
HYDROGEN
,
HELIUM
,
H20
(default:
NITROGEN
)
Query:
@253GT?;FF
Query Response:
@253ACKAIR;FF
Command:
@253GT!NITROGEN;FF
Command Response:
@253ACKNITROGEN;FF
Vacuum adjustment – VAC
The VAC command zeroes the MicroPirani™ readout. Evacuate the transducer to a pressure below 8×10
-6
Torr before performing vacuum adjustment. Optionally, the user can adjust for zero by pressing the ZERO
switch on the evaluation board, as described in the section Adjustment for Zero.
Command:
@253VAC!;FF
Command Response:
@253ACKVAC;FF
