User Manual
E126-P-EG
Page 28
FW_E126-P-EG_M_v0301-01_EN
5
TEMPERATURE - WITH TYPE TA (4-20MA)
5.1 DISPLAY
Programs the displayed temperature unit. This setting does not influence
the actual calculations.
5.2 SPAN
Determines the measurement range in Kelvin (K) of the (0)4-20 mA
temperature sensor.
Example: Calculating the span for temperature
.
The sensor generates:
●
the minimum signal (4 mA) at a temperature of - 100°C (173.15 K).
●
the maximum signal (20 mA) at a temperature of 250°C (523.15 K).
Therefore, the span should be set at (523.15 – 173.15 =) 350 K.
After pressing PROG, the decimal point will start to flash. The decimal
position can then be changed by pressing the SELECT-key, then press the
CLEAR key to set the digits.
5.3 OFFSET
Calculations are based on temperature values in Kelvin (K).
The flow computer needs to know the measured temperature at minimum
signal. In the above example 173.15 K must be entered.
5.4 FILTER
Stabilizes the temperature reading. This digital filter setting produces a
more stable but less actual reading.
The filter principal is based on three input values: the filter level (01-99), the
last calculated temperature, and the last average value. The higher the filter
level, the longer the response time of a changed value. Use trial and error
to find the best setting for your application.
RESPONSE TIME ON STEP CHANGE OF INPUT VALUE (IN % OF END VALUE)
Filter value
50%
75%
90%
99%
01
filter disabled
filter disabled
filter disabled
filter disabled
10
7 sec
14 sec
22 sec
44 sec
20
14 sec
28 sec
45 sec
90 sec
30
21 sec
41 sec
68 sec
136 sec
50
35 sec
69 sec
114 sec
228 sec
75
52 sec
104 sec
172 sec
344 sec
99
69 sec
137 sec
227 sec
454 sec
5.5 CALIB-LOW
Calibrates the input value for (0)4 mA. This setting is used because the
signal from the temperature sensor might not be exactly 4.0 mA (or 0.0 mA)
at minimum temperature. This function measures the real output value at
minimum temperature.
Make sure the offered signal is correct before calibration takes place
as this has a major effect on the accuracy of the system.
After pressing PROG, three settings can be selected:
●
CALIB: Calibrates the input with the actual "(0)4 mA" value. After
pressing enter, CAL SET is displayed as soon as calibration is
completed. From that moment, the analog value must be more than the
calibrated value before the signal will be processed.
●
DEFAULT: Reinstalls the manufacturer’s value.
●
CAL SET: Selects the last calibrated value.
5.6 CALIB-HIGH
Calibrates the input value for 20 mA as the signal from the temperature
sensor might not be exactly 20.0 mA at maximum temperature. This
function will measure the real output value at maximum temperature.
Make sure the offered signal is correct before calibration takes place
as this has a major effect on the accuracy of the system.
After pressing PROG, three settings can be selected:
●
CALIB: Calibrates the input with the actual “20 mA” value. After pressing
enter, CAL SET is displayed as soon as the calibration is completed.
From that moment, the analog value must be less than the calibrated
value for a reliable measurement.
●
DEFAULT: Reinstalls the manufacturer’s value.
●
CAL SET: Selects the last calibrated value.
