Rosemount FISHER-ROSEMOUNT 244EH, Руководство по эксплуатации продукта

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3-7
D) If an open sensor is validated at the end of the first update cycle
(Time = 500 ms), the output will go directly to alarm level. The
original spike (at Time = 0 ms) will not be seen at the output.
Case 3: Temperature Change Within the
Threshold Value (2 % of Range)
If the transmitter detects an input change that is within the threshold
value, it reports the new value within one output cycle (500 ms).
Intermittent Sensor
Algorithm and Damping
If the transmitter has both intermittent sensor detect and damping
enabled, the output reading is calculated by the following formula:
The transmitter outputs the corresponding value on the damping curve
within 1.75 to 2.0 seconds and updates the output reading every 500 ms
thereafter, according to the damping equation above. At the value to
which the damping time constant is set, the transmitter output is at
63% of the input change.
0 500 1000 1500 2000 2500 3000 3500 4000
Step Changes Greater than Threshold Value
Input
Time (in 500 ms increments)
Output without Algorithm
Output with Algorithm (Default)
Total of All Step Changes
0 500 1000 1500 2000 2500 3000 3500 4000
Open Sensor
Input
Time (in 500 ms increments)
Output without Algorithm
Output with Algorithm (Default)
False Output
Alarm
Damped Value P N
–
( )
2
T U –
2
T U
+
------------------
 
 
×
N
+
=
P = previous damped value
N = new sensor value
T = damping time constant
U = update rate