Salter Brecknell PS500 - Manual (Page 7)

zero-point. Move away any weight on the scale. Press TARE button to confirm,
or press ON/OFF/ZERO to exit this mode.
6. When ‘CAL.P1’ is displayed, the scale will be calibrated on second calibration
point. The default standard weight is 50%FS, and at the same, you can press
ON/OFF/ZERO to exit the calibration mode. Or load 12.5%-100%FS weight,
and use PRINT/HOLD and UNIT keys to input the loaded weight. If the input
data is larger than 199999, it will show as “Hxxx” and “Lxxx”. If the triangular
symbol on the left bottom of LCD window appears, it means that the digit being
changed is the displayed most significant bit which can only be 0/blank or 1. Press
TARE key to confirm your setting and the indicator will flash the input standard
weight. Wait till the scale comes steady, and input A/D data as per the standard
weight.
The indicator will automatically go to next step, if the second point can be
calibrated correctly. If there’s an error occurred, the scale will display “CAL. Er”
and return back to step 5 for re-calibration.
7. When ‘CAL.P2’ is displayed, the scale will be calibrated on third calibration
point. When xxxxxx kg (or lb) is displayed (100% FS is default), you can press
ON/OFF/ZERO to exit the calibration mode or Place a standard weight (must
be in the range of 25%-100% FS, and equal or larger than that for the second
calibration point; this is also the range of your input number) on the scale. Use
PRINT/HOLD and UNIT key to input the standard weight’s value. Use TARE
key to confirm the standard weight and input number are correct. If the
calibration weight for third point is same with that for second point and the
calibration weight is more than 25%FS, input the standard calibration weight
same as second point calibration and press TARE key to confirm the setting. The
indicator will flash the input weight. If the indicator get reasonable data (the input
weight is correct, and the calibration weight of third calibration is more than
equal to the calibration weight of second calibration), it will go to next step
automatically. If there’s an error occurred, the scale will display “CAL. Er” and
return back to step 5 for re-calibration.
8. When ‘CAL.P0’ is shown again, that means the scale will calibrate scale’s
zero-point again. Now, you can press ON/OFF/ZERO to exit the calibration
mode; or Move away any weight on the scale, press TARE key to confirm; the
displayed data will blink. If the indicator gets reasonable data, it will calculate and
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store all parameters in EEPROM. And then it will auto-reset and display all
segments of LCD, full capacity… like power on again. If there’s an error occurred
in calibration, the scale will display “CAL.Er” and try to repeat from step5. The
scale will return to normal weighing mode.
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Ⅳ. DISPLAY ADC CODE OR INPUT WORKING VOLTAGE VALUE
1. In normal weighing mode, press and hold down ON/OFF/ZERO and
HOLD/PRINT key more than 3s, until ‘codE’ is shown, this means you have been
in display inner code mode; but first, the indicator will show the firmware version
“xx.xx.xx”. In this mode, you can examine the inner working voltage, the stability
of weighing system, the variety value of A/D data as per the loaded weight.
NOTE:
1) The increment of A/D code for FS weight must be larger or equal to 2 times
of selected display division-n; otherwise, the calibration cannot be properly
completed. Eg. The display division is 0.1kg. Load 100kg standard weight
on the platform, the increment of A/D code is at least 2x 100kg/0.1kg=
2x1000=2000. In this case, the scale can be calibrated. Otherwise, smaller
division needs to be chosen.
2) The data should be stable; otherwise, the calibration cannot properly
complete.
2. In this mode, you can calculate the proper ADC data at zero point by examining
the A/D data for loaded weight. If the ADC increase for full capacity is NFS, the
power-on zero range is set to Zp% FS (P12 setting) and zero key range is set to
Zk% FS (P13 setting). Then proper ADC data of zero point is larger than (Zp%+
Zk%) x NFS.
ADC increase for full capacity (N FS ) can be making out by: Load the weight W on
the platform, and the ADC increase for W weight is Nw. The ADC increase for
full capacity W
FS is (N FS )= (Nw)x (W FS )/W .
Negative value may be displayed because of error connect of loadcell or error
position of the zero-point potentiometer on PCB; however, the software only
deals with positive value. So, is you are the position of zero-point potentiometer
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