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Vaisala PTB200 User Manual

Page 16

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PTB 200

15 (28)

Digital Barometers

SSD/Operating Manual

24th February 1993

PTB200-O0284-1.1

FILT

Setting the filter parameters

FILT xxx yyyy

where
xxx

ON or OFF

yyyy

FAST or SLOW

The FILT command is used to set additional numerical filtering modes.

FAST mode introduces a multiplication factor of 4 to the integration time
set with the MTIM command. In addition a special algorithm that takes
the derivative of the pressure change into account is used.

SLOW mode introduces a multiplication factor of 16 to the integration
time set with the MTIM command. No derivative of the pressure change
is taken into account.

The filter settings also affect the settling time of the barometer.

Example of setting the integration time to 5 seconds (MTIM 50, filter
FAST):

>MTIM
Mtim : 64 ? 50
>FILT ON FAST
Press. filter : ON
FAST

Example of setting the integration time to 60 seconds (MTIM 150, filter
SLOW):

>MTIM
Mtim : 50 ? 150
>FILT ON SLOW
Press. filter : ON
SLOW

>FILT OFF

turns the filter mode off. Then only the MTIM command affects the inte-
gration and settling times.