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3. OPERATION
Caution:
When used with type ‘d’ flameproof protection, do not open cover when
circuits are energized nor when hazardous gasses might be present.
Model HIR user interface consists of an LCD display and 4 setup pushbuttons. The temperature characteristics of
the display are such that you should only calibrate the unit when the ambient temperature is between 0
F and
+140
F (-18
C t60
C). Outside this temperature range, the transmitter will operate properly, but the
display may be difficult to read.
Pushbuttons:
Pressing the UP button causes the value displayed to be incremented. Holding the button down causes
the value to continue upward at an ever-increasing rate.
Pressing the DOWN button causes the value displayed to be decremented. Holding the button down
causes the value to continue downward at an ever-increasing rate.
NEXT
Pressing this button shifts the display to the next setup parameter.
SAVE
Pressing the SAVE button saves all calibration values and setup parameters. The display will indicate
"Saving..." to verify that the values are being saved.
3.1 Setup Parameters
IR Temp
This parameter displays the temperature as measured by the infrared sensor. When
displaying this parameter, the signal strength is also displayed. (Refer to section 3.4
Preventative Maintenance: Signal Strength.)
LOOP mA
Loop current transmitted in milliamperes
LOOP %
Loop current as a percentage where 0 % = 4 mA and 100 % = 20 mA
Units
This parameter sets the units of measure for temperatures. Use the up or down arrows to
toggle between degrees Fahrenheit and Celsius.
4mA =
Zero scale temperature, i.e., the temperature corresponding to 4.00mA loop current.
20mA
Full scale temperature, i.e., the temperature corresponding to 20.00 mA loop current.
Lo Alarm
Low alarm setpoint – If the measured temperature falls below this setpoint, the Low Alarm
bit will be set in the HART Device Status and an exclamation (!) will appear next to the
displayed temperature.
Hi Alarm
Hi alarm setpoint – If the measured temperature rises above this setpoint, the High Alarm
bit will be set in the HART Device Status and an exclamation (!) will appear next to the
displayed temperature.
Sig Alarm
Signal level alarm setpoint – If optical occlusions cause the amount of light reaching the
sensor to fall below this level the Signal Alarm bit will be set in the HART Device Status
and ‘LOW!” will appear in the signal display field when displaying the IR TEMP parameter.
Enter a number between 0 and 100 where 0 means light is completely blocked. 100
means no blockage. Typical values would be 50 to 70.
