PCB Piezotronics 441A35 - Setting the Output Sensitivity; Setting the Time Constant

443B101/443B102 4
Manual 19854 Rev. D
ECN 50523
by pressing the right-facing arrow.
2. Press the MENU button again and the cursor is
now in the sensor sensitivity position.
3. Enter the sensitivity for the selected
accelerometer using the keys with up and down
arrows. Note that if the up or down key is held,
the display will increment or decrement
continuously.
4. Press the MENU key again and the selected
charge sensitivity now shows on the Model
443B’s display.
Setting the Output Sensitivity
1. Press the MENU button. Move the cursor to
OUT.
2. Press the MENU button again and the cursor is
at the output position. Set the output to the
desired setting.
3. Press the MENU button again and the desired
output setting shows on the Model 443B.
Setting the Time Constant
1. Press the MENU button again and select the LF
position.
2. Press the MENU button again, and the display
shows:
0.2 Hz 2.0 Hz.
Low Freq. Sel.
Select the suitable lower-limiting frequency of 2
Hz for sensors with high temperature transient
sensitivity.
3. The Model 443B102 includes medium and long
TC options as well. To access them, press the
down key again. The display shows:
Med TC Long TC
Low Freq. Sel
4. Press the MENU button again after selecting the
desired setting. For 0.2Hz, 2Hz and med TC the
Model 443B now indicates the selected setting.
Verify the setting by the indication on the front
panel.
5. If long time constant is selected in charge mode
(443B102 only), the display will briefly indicate:
Time Constant is >10,000 sec
or:
Time Constant is >100,000 sec
depending on the gain selected. And then:
Autozero in Progress
The autozero function zeros the output to
within 50 mV of ground.
6. The next display will be:
Null Drift?
Yes No
The 443B102 has a built-in automated drift
nulling routine which ensures that the drift is
well within the stated specification. This should
be run after the unit has been on for at least
one hour in long TC mode to allow for proper
warm up time. Selecting “Yes” begins the
routine. The internal microprocessor will then
begin adjusting the leakage current so that the
drift is minimized. The process may take up to
about 10 minutes, depending on how much
adjustment is necessary.
It is recommended that the sensor be
disconnected during nulling so that the
input is not disturbed.
During nulling, the display will show:
Nulling Drift
Comp Lvl = X.XXX
Where X.XXX is the voltage used internally to
adjust the drift. It may range between 5v. If it
is necessary to terminate nulling before it is
complete, press the MENU key and the unit will
return to normal operation. Once the nulling
has been completed, the LCD will return to the
operating display.
7. If the microprocessor is unable to satisfactorily
null the drift, the LCD will display:
Unable to Null
Try Again Exit
Selecting “Try Again” will begin the nulling
routine, while “Exit” will return the unit to
normal operation. Common reasons for failing
to null are insufficient warm up time, or leaving
the sensor connected to the input.