Question

A load cell is calibrated in an environment at a temperature of 21C and has the following deflection/load characteristic:

Answer 1

2)

a) Sensitivity is linear at 1mm/50kg=0.02mm/kg at 21℃. At 35℃ there is a zero-load bias which must be deducted from the readings, so the readings are 1.1, 2.2, 3.3, 4.4 mm for 50, 100, 150, 200 kg respectively. The sensitivity at 35℃, the sensitivity is 1.1mm/50kg=0.022mm/kg and is still linear.

b) Zero drift is 0.2mm and sensitivity drift is 0.002mm/kg, between 21 and 35℃.

c) The temperature difference is 35-21=14℃. So the coefficient for zero drift is 0.2mm/14=0.0143mm/℃; and for sensitivity is 0.002/14=0.000143mm/kg/℃.

In other words: 0.0000143m/℃, 0.000000143m/kg/℃.