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Reference Manual

00809-0200-4728, Rev RA

Section 2: Configuration

April 2015

Configuration

The value chosen for damping affects the response time of the transmitter. When set to zero

(disabled), the damping function is off and the transmitter output reacts to changes in input as

quickly as the intermittent sensor algorithm allows. Increasing the damping value increases

transmitter response time.

With damping enabled, if the temperature change is within 0.2% of the sensor limits, the

transmitter measures the change in input every 500 milliseconds (for a single sensor device) and

outputs values according to the following relationship:

At the value to which the damping time constant is set, the transmitter output is at 63% of the

input change and it continues to approach the input according to the damping equation above.

For example, as illustrated in Figure 2-14, if the temperature undergoes a step change—within

0.2% of the sensor limits—from 100 degrees to 110 degrees, and the damping is set to 5.0

seconds, the transmitter calculates and reports a new reading every 500 milliseconds using the

damping equation. At 5.0 seconds, the transmitter outputs 106.3 degrees, or 63% of the input

change, and the output continues to approach the input curve according to the equation above.

For information regarding the damping function when the input change is greater than 0.2% of

the sensor limits, refer to “Intermittent Sensor Detection” on page 35.

Figure 2-14. Change in Input vs. Change in Output with Damping Set to 5 Seconds

Damped Value NP–()

2TU–

2TU+

------------------





× P+=

P = previous damped value

N = new sensor value

T = damping time constant

U = update rate

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