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 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 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 by the software, based on the load cell calibration information, to the proper gram readout.
The RAW COUNT numbers are more useful in diagnosing load cell problems because they eliminate 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. |
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¦ | 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) | ¦ |
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A floating, drifting number usually indicates the | load cells | are not | |||||
plugged in. |
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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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