Fisher 244ER, 244EH manual seconds, the transmitter outputs the reading that corresponds to

Rosemount Models 244EH and 244ER PC-Programmable Temperature Transmitters

Figure 3-3. Damping Function when Input Change is Greater Than the Threshold Value

Figure 4-1illustrates an example of intermittent sensor detect with damping enabled. If the temperature undergoes a step change greater than the threshold value, or from 100 degrees to 110 degrees, and the damping is set to 5.0 seconds, the transmitter calculates a new reading every 500 ms using the damping equation, but holds the output at 100 degrees for between 1.75 and 2.0 seconds. Within 1.75 and

2.0 seconds, the transmitter outputs the reading that corresponds to

the damping curve at that time ( ), and continues to calculate and

update the output reading every 500 ms thereafter ( ) according to the damping equation. After 5 seconds, the transmitter outputs

continues to approach the input curve￿according￿to the￿equation above.

106.3 degrees, or 63% of the input change ( ), and the output

NOTE

If the damping time constant is set between 0 and 2 seconds, the transmitter does not report the output change until the intermittent sensor algorithm validates the input signal. After validating the input signal, the transmitter outputs the value that corresponds to the damping curve at that time.

644-644_02A

Intermittent Sensor Detect (Advanced Feature)

NOTE

The Intermittent Sensor Detect feature is not available when using a Model 244EH with software revision 5.5.1. To determine the software version of a Model 244E temperature transmitter, first connect the transmitter to the Model 244EC configurator, open the Model 244EC software configuration tool, and then choose “service” from the Model 244EC software menu.

The Intermittent Sensor Detect feature is designed to guard against process temperature readings caused by intermittent open sensor conditions (an intermittent sensor condition is an open sensor condition that lasts less than 0.7 seconds). By default, the transmitter is shipped with the Intermittent Sensor Detect feature switched ON. In most applications, this is the preferred setting. The Intermittent Sensor Detect feature can be switched ON or OFF with the Model 244EC. The setting of this feature cannot be changed when using a Model 244E with version 5.5.1 software and a Model 244EC version 2.0 or earlier.

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