### Power Monitoring

Current Sensors and Transducers

Current Transformers

Power Meters

### Building Automation

Calibration

Critical Environments

Energy Management

HVAC/R OEM

HVAC/R

## Setra Blog

#### by Tom Lish

Total Error Band (TEB) is a measurement of worst case error; it is the most comprehensive and concise measurement of a sensors true accuracy over a compensated temperature range.  TEB is extremely important to know when trying to determine how well a sensor will work within a particular design system. By calculating TEB you'll be able to understand the different possibilities for error. Formulating TEB can be tricky if you don't have the right inputs readily available.

There are five different factors that are considered for worst case error.

ACCURACY:

Non-Linearity

• Best Fit Straight Line (BFSL) Method: Relationship of a calibration curve to specified straight line.
• End Point Method: Relationship of a calibration curve to a specified straight line through its end points.
• Terminal Method: Relationship of a calibration curve to a specified straight line with end points at zero and full scale.

Non-Repeatability: The ability of a transducer to reproduce output readings when the same pressure value is applied to it consecutively, under the same conditions, and from the same direction.

Hysteresis: The maximum difference in output at any pressure value within the specified range, when the value is approached increasing and decreasing pressure.

ZERO OFFSET: Zero output is factory set to within a certain % of full scale. Results in a shift up or down of the calibration curve. Does not affect linearity or accuracy.

SPAN OFFSET: Span output is factory set to within a certain % of full scale. Results in a change in the slope of the curve. Does not affect linearity or accuracy.

ZERO TEMPERATURE OFFSET: The change in the zero offset due to temperature changes.

SPAN TEMPERATURE OFFSET: The change in the span offset due to temperature changes.

Setra's AccuSense™ line of products offers a 0.25% TEB specification over a temperature range of -20°C to 60°C for each of its transducers.  This specification gives you, the user,a more comprehensive look at the sensor's performance in real world installations.

CLICK HERE to view Setra's Model ASL, one of the two transducers in our AccuSense™ product line.