G4 Multi Channel Weighing Instrument. PM/DT/HE Technical Manual

G4 Multi Channel Weighing InstrumentNumber of scale divisionsThe number of scale divisions (div.) for a scale = ‘Capacity’ / ‘Resolution’.To get correct and stable weight display, parameter ‘Resolution’ should beset so that the number of scale divisions with the selected ‘Capacity’ isless than 6 000 (10 000).The number of scale divisions is also limited by the performance of the transducersand by how large a portion of the transducer capacity thatis actually utilised.To ensure a stable weight display, the input signal to the instrumentshould exceed 0.2 μV/scale division.Example:• Three transducers, each of 20 000 N (approx. 2 000 kg), are to support a tankwhich, without contents, weighs 3 500 kg. The amount of material in the tankvaries 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 000Signal/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 000Signal/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 andsignal/div. are on the borderline in Case 1. In some special casesthe resolution may obviously be driven higher, but the transducercharacteristics must always be observed.4-3