Hysteresis is the difference of two separate measurements taken at the same point, before and after a physical quantity is increased and decreased.

# Errors

## LHR – Linearity, Hysteresis and Repeatability

Linearity, Hysteresis and Repeatability (LHR) is often used to describe the room temperature precision of a pressure sensor, excluding all zero & span offsets, temperature errors and long term stability. Also see non-linearity and pressure hysteresis.

## PPM – Parts Per Million

Parts Per Million (PPM) is a ratio used to describe the maximum measurement error or resolution of pressure measurement equipment.

## Secondary Pressure Standard

Secondary Pressure Standards are pressure calibration instruments which have to be checked by primary pressure standards on a regular basis.

## TSS – Thermal Span or Sensitivity Shift

Thermal Span or Sensitivity Shift signifies the maximum amount of span that will change at any measurement point within the compensated temperature range.

## TEB – Total Error Band

Total Error Band (TEB) is the difference between the most negative and most positive deviation from the true measurement, determined from the combination of all known errors for a sensing device, within the constraints of the measurement and operating temperature range. Typically in the case of a pressure measurement device for example, the total error […]

## Span Offset

Span Offset is the amount of deviation in output or reading from the exact value at a point within the measurement span.

## TZS – Thermal Zero Shift

Thermal Zero Shift (TZS) is the maximum amount the output or reading at the null measurement point might deviate over the compensated temperature range

## Thermal Hysteresis

Thermal Hysteresis is the measured change in output or reading at a specific measurement point taken during a sequence of increasing and decreasing temperature.

## TEB – Temperature Error Band

Temperature Error Band (TEB) is the error derived from the most positive and negative deviation of all measurement points within a measurement range over the operating or compensated temperature range.

## Temperature Error

Temperature Error is the deviation of a measurement reading caused by a change in media or environmental temperature.

## Temperature Compensation

Temperature Compensation is a correction applied to a measurement instrument to reduce errors attributed to temperature changes in a process media which is being measured or in the surrounding environment that the instrument is being used.

## Repeatability

Repeatability is the amount of change in a measured reading at the same measurement point after a defined number of cycles over the measurement range or a set of environmental limits.

## RTE – Referred Temperature Error

Referred Temperature Error is the max deviation expressed as a +/- %FS from measurements taken at a defined temperature.

## Accuracy

Accuracy of a measurement instrument defines how much a measurement value may deviate from the perfect measured value.

## NL – Non-Linearity

Non-Linearity is the deviation error derived from the straightness of a set of recorded measurements when compared to a straight line, such as bsl or tsl, drawn through all the results. The maximum non-linearity error is normally expressed as a percentage of full scale.

## BSL – Best Straight Line

Beast straight line (BSL) is the mathematically derived straight line which runs through the middle of a set of readings in such a way to achieve the smallest error across all the results. The measurement precision of a device is often specified in relation to the maximum deviation from the best straight line.

## Calibration Error Calculator

Use this calibration error calculator to determine the accuracy of a measurement device which has a linear input and output characteristic.