- 19 -
12. LOAD CELL & MICROVOLT INPUT
Notes
1.
See Section 19 to select 10V excitation.
2.
Jumpers are 2.5 mm (0.1 in).
SCALE & OFFSET SETUP
For absolute readings in millivolts or microvolts,
select
_
dC u
under
_
InPut
. Also select a
scale factor of 1 and an offset of 0. A full scale reading is 20,000 counts. Decimal point selection
does not affect the displayed digits. For example, 20 mV can be displayed as 20.000 mV or
20000 µV.
For ratiometric readings with bridges,
such as load cells, select
_
Strn
under
_
InPut
. Scaling
is normally set up from the front panel using the
and
keys, but can also be set up via
RS232/485 using our PC compatible setup software (available at no charge). A full scale reading
is 20,000 counts. Three scaling methods are selectable: 1) Manual scale and offset, 2)
Coordinates of 2 points, and 3) Reading coordinates of 2 points. Please see the Glossary for an
explanation of each method.
The reading coordinates of 2 points scaling method
applies a straight line fit between two
points, which are based on actual transducer signals. A low input signal, such as the signal with
zero weight, and a high input signal, such as the signal with a known weight, are applied to the
meter. The corresponding desired low and high readings are then entered from the front panel.
The meter applies straight line fit between these low and high calibration points. This scaling
method has the advantage of calibrating the transducer and meter as a system. The actual
voltages or currents at the two endpoints do not need to be known. This method can be used
with DC, process and load cell meters when known inputs are available. It is also available for
AC meters, but not thermocouple or RTD meters.
Load Cell, Strain Gauge and Microvolt meters utilize the load cell signal conditioner board, which
offers sensitivity to ±20 mV full scale and 4 or 6-wire load cell connection. This board needs to
be configured via jumpers for the desired voltage range. All signal ranges are factory calibrated
with calibration factors stored in EEPROM. The meter software recognizes the board and will
bring up the appropriate menu items for it; however, it does not recognize the jumper settings.
Please see further manual sections for setup of the following features:
, and
RANGE SELECTION VIA JUMPERS
Ranges & Display with
Scale Factor = 1
Input
Jumpers
Counts
±20.000 mV
±50.000 mV
±100.00 mV
±250.00 mV
±500.00 mV
e
a
b
c
d
±20000
±50000
±10000
±25000
±50000
