Conair GB - Manual (Page 87)

LOAD CELL RAW SIGNAL READOUT
Press "CE" key to check this RAW number for several seconds.
Load cells put out a very small voltage that varies slightly as the
load cell is deflected. This voltage is converted, on the circuit
board, to a pulse train and these pulses are counted for 1 full second
to determine a weight load. The software can handle a range of counts
from 0 to approximately 249,850.
A properly operating set of 3 K cells will range from about 55,000 to
120,000; a span of about 65,000 from empty weight (weigh bin in place),
to a full bin weight of 2000 grams. (10 K load cells range about
90,000 from empty to a full 9000 grams). The system will work correctly
as long as the empty bin weight readout is between 1 and 149,248.
149,248 is the highest number that the software will accept for zero
weight calibration (see parameters, LCZ). If the number is over this
when you press the ZERO weight key, the display will say (ZERO LOW).
This RAW COUNT number is converted to the proper gram readout, by the
software, based on load cell calibration information.
The RAW COUNT numbers are more useful in diagnosing load cell problems
because they bypass the calibration math and, therefore, bypass any
calibration errors that might have occurred.
Press "CE" key to display this RAW number for several seconds.
To observe this number continuously, use the *98 function in the
PROGRAM mode.
Press: * Display will say: (PASSWORD)
Press: 22222 Display will say: (P x)
Press: * Display will say: (INSTR --)
Press: 98 Display will say: (CNT OFF )
Press: * Display will say: (CNT ON )
Press: EXIT Display will say: (P xxxxx)
A floating, drifting number usually indicates the load cells are not
plugged in.
A readout of 0 indicates an open circuit, a damaged wire or cell.
A full scale readout of 249,850 indicates a damaged wire or cell.
A set of 3 K load cells will put out about 33 more counts for every
gram of weight that is added. A test of sensitivity is to add a small
weight to the bin. The RAW WEIGHT count should increase by about 33
counts for each gram added. (10 counts per gram for 10K load cells.)
If you call us for help in solving a load cell problem, it is helpful
if you can tell us what the RAW COUNT number is with the bin empty, and
with a known weight in it. Pressing the CE key at any time will
display the RAW COUNT number for the current weight.
To OPERATE with DAMAGED load cells in a VOLUMETRIC mode,
see KEYPAD, *87, Volumetric mode.
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