Watlow D4T Data Logger
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Chapter 5 Function Reference
Signals
Direction
Label
Type
Function
Receivers
A
Analog
The input for the low end of the range
B
Analog
The input for the high end of the range
Transmitter - - - - Analog
When A is below the crossover band the output is the fil-
tered value of A plus the offset.
When A is in the crossover band the output is the filtered
weighted average of the inputs plus the offset.
When A is above the crossover band, the output is the fil-
tered value of B plus the offset.
Function
To gradually transition from one input to another over a user-defined range, set Function to
Crossover
.
Crossover Point
Set the middle of the band over which the function transitions between inputs A and B.
Range: -99,999.000 to 99,999.000 seconds
Crossover Band
Set the width of the transition between input A and B.
Range: -99,999.000 to 99,999.000 seconds
Offset
Adjustment added to the output.
Range: -99,999.000 to 99,999.000
Filter
Set the amount of filtering to apply. Filtering smooths signal fluctuations. Increase the time to
increase filtering. Excessive filtering slows the function’s response.
Range: 0.0 to 60.0 seconds
Wet Bulb / Dry Bulb
This function calculates the relative humidity of an environment based on two measured tem-
peratures: the air temperature (dry bulb) and the temperature reached by evaporative cooling
(wet bulb). A filter and offset may be applied to the calculated value. The output is in per-
cent relative humidity.
This method for determining relative humidity applies in the temperature range 10 to 350°F
(-12°C to 177°C).
Signals
Direction
Label
Type
Function
Receivers
DRY
Analog
The dry temperature measurement
WET
Analog
The wet temperature measurement
Transmitter - - - - Analog
The filtered relative humidity plus the offset