- -
12
12)
BAUD_RATE (only HD21...4.2):
indicates the frequency used, expressed in kHz, for the
serial communication with the PC. Values from 1.2 (1200 baud) to 38.4 (38400baud). Use
the arrows to modify this parameter and confirm using ENTER.
The communication
between instrument and PC (or serial port printer) only works if the instrument and
PC baud rates are the same
. If the USB connection is used this parameter value is
automatically set (please see the details on page 25).
PEAK key - only HD21...4.0
PEAK/MENU key - only HD21...4.2
The PEAK
(HD21...4.0)
or PEAK/MENU
(HD21...4.2)
keys enable the pressure peak measurement
circuit. The Peak indication blinks and the current pressure is shown. When a peak is detected (a
positive variation greater than 5% compared to current measurement), the Peak indication remains
on for 5 seconds and its value is displayed. If, in the meantime, a higher peak than the previous one
is detected, the indication is updated. From 5 seconds after the previously detected peak, the Peak
indication returns to blinking and the current pressure is shown.
To keep the maximum peak on the display, select the peak function and then the record MAX
function using FUNC/ENTER. This way, the display continuously shows the maximum peak
reached during measurement. Before starting new measurements, clear the memory of previous
measurements using "FUNC CLR": please see the FUNC/ENTER key description.
IMPORTANT: the peak measurement works with external probes connected to the
instrument through a SICRAM PP471 module and not with the internal pressure sensor.
The Logging function during peak measurement
(only HD21...4.2)
:
To record the maximum peaks, start the peak function and then the record function (LOG key). As
the measured peak is maintained for about 5 seconds, in order to avoid losing any peak, use 1
second logging intervals. Indeed, using longer times the single event could occur between two
subsequent recording and be ignored.
LOG/DUMP LOG key - only HD21...4.2
In measurement mode, this function starts and stops the logging of a data block to be saved in the
instrument's internal memory. The data logging frequency is set in the "
Print and log interval"
menu parameter. The data logged between a start and subsequent stop represent a block.
When the logging function is on, the LOG indication is displayed, the battery symbol blinks and a
beep is issued each time a logging occurs;
the battery symbol does not appear when using an
external power supply
.
To end the logging, press LOG.
The HD21...4.2 can turn off during logging between one capture and the next: the function is
controlled by the
Sleep_Mode_LOG
parameter. When the logging interval is less than one minute,
the logging instrument remains on; with an interval of at least one minute, it turns off between one
capture and the next if the parameter
Sleep_Mode_LOG
=YES.
