SenSmart 3000 User's Manual
Document: UM-1003
Revision Level B
31
remote from the SenSmart 3000 or if a new sensor is installed. Other input type entries draw a
line through these menus and they are inactive. SenSmart 3000 bridge sensors may be from 2 to
6 volts excitation voltage
at the sensor
. This means if the sensor is mounted a long distance
away the voltage at the SenSmart 3000 may have to be higher to compensate for losses in field
wiring. Be careful not to exceed correct sensor volts at the
sensor’s A and R terminals.
Set Balance
allows balancing of the catalytic bead sensor and must only be performed with
ZERO gas on the sensor (Figure 6-3). Balance is similar to a very coarse ZERO calibration and
does not need to be precise since subsequent calibrations will correct for small errors. ZERO gas
applied to the sensor should provide a Reading of
–3 to +3 on the SENSOR BALANCE menu.
Figure 6-3: Catalytic Bead BALANCE & SENSOR VOLTS Adjust Menus
6.3
Set Gain to Unity (Technicians only!):
Set Gain to UNITY
allows resetting previous calibration OFFSET to zero and GAIN to one. This
is the definition of UNITY. A calibration should be performed after setting UNITY.
* * * * * WA R N I N G* * * * *
P r e v i o u s C a l i b r a t i o n
w i l l b e e r a s e d .
E D I T t o c o n f i r m.
N E X T t o e x i t .
Ga i n = U n i t y
EDIT
Figure 6-4: Set UNITY GAIN Menu
6.4
PreAmp Gain Adjust (Technicians only!):
Depending upon
Input Type
, SenSmart 3000 inputs range from a few micro amps to hundreds of
micro amps.
PreAmp Gain Set
is the adjustment that matches the input signal range to the
SenSmart 3000 input signal conditioning circuits. Altering the PreAmp Gain setting automatically
resets previous calibration OFFSET & GAIN values to UNITY as described in section 6.3.
If it is determined the PreAmp Gain value is incorrect, apply the desired up-scale input and use
the UP / DOWN keys to obtain the correct
Reading
value.
Counts
are the 10-bit binary A/D
value with an active range value of 0 - 1023.
CAUTION:
For standard installations, this is a factory adjustment. Do not use the
PreAmp Gain
Set
menu for calibrating sensors. It should only be adjusted if a new measurement gas or input
range is required.
P GA S e t u p
Ga i n 2 5 . 0 %
C o u n t s 10 11
R e a d i n g 10 0
U p / D n t o C h a n g e .
N e x t t o e x i t .
Figure 6-5: PreAmp Gain Adjust (PGA) Menu
