Non-Linear Calibrations

Not every calibration is linear.

Although ARDI initially assumes that your calibration will be linear - breaking your range up into evenly spaced segments depending on your point count - you can override this behaviour.

For example, let's look at a flowmeter calibration.

This flowmeter is measuring flow speed. It has a linear input between 0 and 20 m/s.

It has a digital display reading in L/s. Although this is a radically different scale than speed, it's still linear - a movement between 2 and 4s will double the speed on the display.

But the output is a square-root output, which is often used (particularly in older systems) to mask signal noise at the low-end of the instruments sensitivity.

This calibration needs three properties.

Range - Input,
Range - Output and
Range - Display.

Once all three are present on your asset, you'll need to go to the Asset Maintenance Page and choose Calibration Settings.

Here you can fine-tune the actual calibration points against one-another.

Choose one of these columns - normally your input - to be linear, and alter the other columns to have matching values.