Dwyer CDTR User Manual
Page 3
RON
ROf
DSp
UNI
COL
COH
Menu Descriptions
Relay on set point
Sets the CO
2
concentration which the optional relay is energized.
Low limit: 0 PPM
Factory setting: 1000 PPM
High limit: 2000/5000 PPM (depending on model)
Relay off set point
Sets the CO
2
concentration which the optional relay is de-energized. Setting
value lower than RON provides direct action for detecting high concentrations of
CO
2
. Setting value higher than RON provides indirect action for detecting low
concentrations of CO
2
. or on the LCD display will be lit to indicate
when the relay is energized.
Low limit: 0 PPM
Factory setting: 950 PPM
High limit: 2000/5000 PPM (depending on model)
Display configuration
Determines the LCD display configuration during normal operation. The LCD
display can indicate the CO
2
concentration, temperature, relative humidity
(CDTR only) and CO
2
concentration combined with temperature or relative
humidity (CDTR only).
CH CO
2
concentration and relative humidity (CDTR only)
CT CO
2
concentration and temperature
C CO
2
concentration only
T Temperature only
H Relative humidity only (CDTR only)
Units selection
Temperature and barometric pressure measurements can be displayed in US
engineering units or SI engineering units. The factory default is to display US
engineering units.
US units F for temperature and in Hg for barometeric pressure
SI units
C for temperature and hPa for barometric pressure
CO
2
low output range
Sets the CO
2
concentration for the lowest output (4 mA or 0 VDC).
Low limit: 0 PPM
Factory setting: 0 PPM
High limit: 2000/5000 PPM (depending on model)
CO
2
high output range
Sets the CO
2
concentration for the highest output (20 mA, 5 VDC or 10 VDC).
When COH is set above COL, the transmitter is direct acting and the output will
increase with an increase in CO
2
level. When COH is below COL, the
transmitter is reverse acting and the output will increase with a decrease in CO
2
level.
Low limit: 0 PPM
Factory setting: 2000/5000 PPM (depending on model)
High limit: 2000/5000 PPM (depending on model)
Temperature low output range (CDT with active temperature only)
Sets the temperature for the lowest output (4 mA or 0 VDC).
Low limit: 32.0°F / 0.0°C
Factory setting: 32.0°F / 0.0°C
High limit:
122.0°F / 50.0°C
Temperature high output range (CDT with active temperature only)
Sets the temperature for the highest output (20 mA, 5 VDC or 10 VDC).
When TOH is set above TOL, the transmitter is direct acting and the output
will increase with an increase in temperature. When TOH is below TOL, the
transmitter is reverse acting and the output will increase with a decrease in
temperature.
Low limit:
32.0°F / 0.0°C
Factory setting: 122.0°F / 50.0°C
High limit:
122.0°F / 50.0°C
Humidity low output range (CDTR only)
Sets the temperature for the lowest output (4 mA or 0 VDC).
Low limit:
0.0%
Factory setting: 0.0%
High limit:
100.0%
Humidity high output range (CDTR only)
Sets the temperature for the highest output (20 mA, 5 VDC or 10 VDC).
When HOH is set above HOL, the transmitter is direct acting and the output
will increase with an increase in temperature. When HOH is below HOL,
the transmitter is reverse acting and the output will increase with a
decrease in temperature.
Low limit:
0.0%
Factory setting: 100.0%
High limit:
100.0%
Barometric pressure
Sets the typical barometric pressure for the location where the transmitter
is mounted. The factory setting is for standard pressure at sea level.
Adjusting the barometric pressure gives a more accurate measurement,
especially at higher elevations. Refer to the elevation charts in Figure 9 for
typical barometric pressures at a given elevation.
Low limit:
20.0 in Hg / 600 hPa
Factory setting: 29.9 in Hg / 1013 hPa
High limit:
32.0 in Hg / 1100 hPa
Calibration
Calibrates the carbon dioxide sensor to a known gas value. Read
calibration instructions before using this feature. Hold
for 5 seconds.
TOL
TOH
HOL
HOH
BAR
CAL