Vishay G4, Technical Manual, Page: 83 / 200

G4 Multi Channel Weighing Instrument
4-3
Number of scale divisions
The number of scale divisions (div.) for a scale = ‘Capacity’ / ‘Resolution’.
To get correct and stable weight display, parameter ‘Resolution’ should be
set so that the number of scale divisions with the selected ‘Capacity’ is
less than 6 000 (10 000).
The number of scale divisions is also limited by the performance of the transducers
and by how large a portion of the transducer capacity that
is actually utilised.
To ensure a stable weight display, the input signal to the instrument
should exceed 0.2
µ
V/scale division.
Example:
•
Three transducers, each of 20 000 N (approx. 2 000 kg), are to support a tank
which, without contents, weighs 3 500 kg. The amount of material in the tank
varies from 0 – 1 000 kg.
•
Transducer capacity = 6 118 kg
(3 x 20 000 N / 9.80665).
•
Transducer sensitivity = 2.039 mV/V.
•
Supply voltage to transducers = 5 V.
•
Signal from transducers at full load (6 118 kg) = 10.2 mV
(2.039 mV/V x 5 V).
•
Signal change in response to an applied load of 1 000 kg = 1.66 mV
(10.2 mV x 1 000 / 6 118).
•
Set 'Capacity' to 1 000 kg.
1. Set 'Resolution' to 0.1.
Number of scale divisions = 1 000 / 0.1 = 10 000
Signal/scale division = 1.66 mV / 10 000 div. = 0.17 µV/div.
2. Set 'Resolution' to 0.2.
Number of scale divisions = 1 000 / 0.2 = 5 000
Signal/scale division =1.66 mV / 5 000 div. = 0.33 µV/div.
It is best to select Case 2, since both the number of scale divisions and
signal/div. are on the borderline in Case 1. In some special cases
the resolution may obviously be driven higher, but the transducer
characteristics must always be observed.