Vaisala PTB 200 A - Page 15

PTB 200 14 (28)
Digital Barometers
SSD/Operating Manual 24th February 1993 PTB200-O0284-1.1
UNIT Setting the pressure unit
UNIT x<cr>
where
x hPa*, kPa, mbar, inHg, mmHg, torr, psia (* factory setting).
Command UNIT is used to select the pressure unit. Type the selected
pressure unit as given above.
Example of changing the pressure unit to mbar:
>UNIT mbar<cr>
MTIM Setting the measurement time parameters
MTIM<cr>
The MTIM command is used to set the number of measurement sam-
ples (MTIM value) integrated to get a pressure reading. The basic
measurement sample time is about 25 milliseconds. The MTIM value
can range from 4 to 255.
The MTIM factory setting of the PTB 200 A is 64; this ensures a stable
resolution of 0.01 hPa. The integration time is then 64 x 25 ms = 1600
ms. The settling time including initialization and integration time is ap-
proximately 2 s.
The MTIM factory setting of the PTB 201 A is 16; this ensures a stable
resolution of 0.1 hPa. The integration time is then 16 x 25 ms = 400 ms.
The settling time including initialization and integration time is approxi-
mately 1 s.
The MTIM value affects the settling time of the barometer: the longer
the integration time, the longer the settling time.
The FILT command also affects the integration and settling times (see
FILT command).
Example of changing the MTIM value:
>MTIM<cr>
Mtim : 64 ? 150<cr>