Vaisala PTB220 - Manual (Page 90)

U SER ' S G UIDE _______________________________________________________________________
84 ___________________________________________________________________ M210194 EN -A
The figure below illustrates in practice the falling edge of the trigger
pulse (lower signal) and the start of pulse outputting (upper signal).
The gate-open time may be calculated in practice using a simple
formula:
maximum number of output pulses
pulse rate (Hz)
+ 0.5 ... 1 second
(D-1)
If SLOW pulse rate (appr. 5 kHz) and LOW resolution (0.1 hPa/mbar)
and no pressure offset have been defined using the PULSE command
then the barometer will output maximum 11.000 pulses at 1100
hPa/mbar pressure. The gate-open time could be 3 seconds.
If FAST pulse rate (appr. 50 kHz) and HIGH resolution (0.01
hPa/mbar) and no pressure offset have been defined using the PULSE
command, the PTB220 series barometer will output a maximum of
110.000 pulses at 1100 hPa/mbar pressure. The gate-open time could
be 3 seconds.
If FAST pulse rate (appr. 50 kHz), HIGH resolution (0.01 hPa/mbar)
and 900 hPa/mbar pressure offset have been defined using the PULSE
command, the PTB220 series barometer will output a maximum of
20.000 pulses at 1100 hPa/mbar pressure. The gate-open time could be
1 second.
If FAST pulse rate (appr. 50 kHz) and LOW resolution (0.1 hPa/mbar)
and no pressure offset have been defined using the PULSE command,
the PTB220 series barometer will output a maximum of 11.000 pulses