Home >> Science & Nature >> Science

How to Calculate Hysteresis

Hysteresis is a measurement of the lag in the variable property of a physical system after a force has acted upon it. For example, if you push the tips of a fork forward, to what extent will the tips return to their original position, and to what extent will they remain pushed forward? The difference in distance between the original position and the position after release provides the calculated hysteresis of the forces. Examples of hysteresis calculations include large geological systems, magnetic materials or the accuracy of sensitive measuring instruments.

Things You'll Need

Barometers
Temperature-controlled chamber
Dead weight pressure tester

Instructions

- 1
  
  Calculating hysteresis is a function of physics.
  
  Apply a pressure of 965 hPa (hectopascals) using a dead weight pressure tester with a barometer to record changes in pressure. Hectopascals are 100 pascals, a standard unit of pressure or stress, and are typically used for barometric pressure measurements.
- 2
  Measure the average indicated pressure on the barometer taken at 965 hPa. This measurement should first be taken on the decreasing pressure part of the cycle.
- 3
  Measure the average indicated pressure at 965 hPa on the increasing part of the cycle. There will be a slight variation between your measurements from this and the previous step.
- 4
  Subtract the barometric pressure in hPa from the increasing part of the cycle from the pressure indicated on the decreasing part of the cycle. The numerical difference between the two readings provides you with the calculation of the hysteresis for the barometers that you are testing.
- 5
  Conduct the same measurements using a control group of barometers and adjust or correct your calculations accordingly. The results that you calculate give you some indication as to the accuracy of the instruments you are using. It also provides a scale by which you can determine the usefulness of the instrument for applications that might require a high level of detail.

Science