then the highest bit transmits “-“
For example:
Indicator displays “12345”, serial port transmits data “=0012345”
Indicator displays “1234.5”, serial port transmits data “=012345”
Indicator displays “-12345”, serial port transmits data “=-12345”
Data frame keeps 7 bits all the time, including radix point
5. Calibration
5.1.
Parameters confirmation
Several parameters need to be confirmed before calibration, including Maximum
weighing value, maximum divisional reading and maximum value. The formula is
Maximum weighing value = Maximum divisional reading * Maximum divisional
value.
The divisional reading usually is from 1000 to 10000, divisional value is 1*10n,
2*10n or 5*10n and n selects value as -3, -2, -1, 1. At a fixed maximum weighing
value, choosing a suitable divisional value must guarantee that uV of each division
is more than or equal to 0.6uV/d. Calculation of uV/d is as following formula:
Divisional value(kg) * sensitivity of load cell output (mV/V) * excitation voltage (V) *1000
uV/d= capacity of load cell (kg) * quantity of load cell (pcs)
Generally, the sensitivity of load cell is 2 mV/V. The exact parameters please take
manual of load cell for reference.
5.2.
Steps of calibration
Calibration should be operated by professional technician. If it is scale applied for
commercial balance, it should be operated under supervision of Legal Metrology
Institution as well.
Following is the steps of calibration:
a. Press [Fn] and [
→
0
←
] buttons simultaneously, indicator displays “
”
b. Press [ PT] button, indicator displays “
”, at this time the value is the
previous calibrated divisional reading, then press [Fn] button to choose
divisional reading.
www.kelichina.com
Page 8 of 17
