Revised 10/12
5
TECHNICAL INFORMATION FOR CDM4160
Table 5 - Signal output in operation mode
3. Operation modes
3-1 Warm up
The sensor is warmed up for two hours after the
module is powered on. The green LED blinks on and
off and a constant voltage (0.4V for -L00, 0.2V for -M00,
0.04V for -H00) is output from the concentration output
port during this period. The green LED will be lit
continuously after the warm-up period ends unless
a power outage occurs.
3-2 CO
2
concentration lower than threshold level
The green LED will be on if the calculated CO
2
concentration is lower than the threshold level.
3-3 CO
2
concentration exceeds threshold level
The red LED will be lit and the control signal output
is turned “ON” if the concentration exceeds the
threshold level.
The control signal output is turned to “OFF” and the
red LED will be off when CO
2
concentration drops
to 90% of the threshold level.
3-4 Trouble
When the sensor's output is abnormal, the yellow
LED blinks on and off and the TRBL signal is set to
“ON.
4. Cautions
1) By assuming that the baseline level represents
fresh air (400ppm of CO
2
), actual CO
2
concentrations
are calculated based on the difference between the
baseline level and the current sensor output. As a
result, the following cautions should be noted:
a) Accurate readings cannot be expected if an accurate
baseline could not be acquired.
b) The sensor should be exposed to fresh air
periodically to properly renew the baseline level.
Performance shown in the specifications cannot be
achieved if the module was used in an environment
where CO
2
concentrations increased slowly and
steadily for a long period of time.
c) The module should be located in fresh air during
the warm-up period. Accurate readings cannot be
expected until the baseline is acquired in fresh air. If
the module is warmed up in an environment where
CO
2
concentration is higher than normal fresh air, the
baseline will represent a polluted level and the device
will not be able to clean the air sufficiently.
d) Power should be on at all times. Since the baseline
is memorized in a microcomputer, if the power should
be cut off, the memory would be lost and operation
would resume from the warm-up process.
e) The module is not intended for usage in life saving
equipment. If the module is incorporated into life
saving equipment, an alternative and secure measure
for calculating CO
2
concentration should be used be
used for the life safety function.
2) This module is designed only for indoor usage.
The module should be protected from exposure to
rain, wind, sun, heat radiation, etc.
3) Please apply a regulated voltage, otherwise the
accurate reading cannot be expected. Application
of excessive and/or reverse voltage would cause
damage to the module.
4) The module does not include a circuit for protection
from excessive current. An excessive current
protection circuit should be added to a peripheral
circuit of the module.
5) The sensor may deteriorate if it is stored without
power in a high humidity environment for a long
period of time. Please keep the sensor in a humidity-
proof bag with a desiccant if the sensor is to be stored
without power for a long period of time.
6) The sensor has dependency on oxygen concentration.
Under environments where the oxygen concentration
Condition
Green LED
Yellow LED
Red LED
Control signal
(CTRL)
Trouble signal
(TRBL)
CO
2
concentration signal
CDM4160-L00 CDM4160-M00 CDM4160-H00
Warm-up period
Blink ON/OFF
OFF
OFF
OFF
OFF
0.4V
0.2V
0.04V
CO2 conc < threshold
ON
OFF
OFF
OFF
OFF
CO
2
conc/1000
CO
2
conc/2000
CO
2
conc/10000
CO2 con > threshold
ON
OFF
ON
ON
OFF
CO
2
conc/1000
CO
2
conc/2000
CO
2
conc/10000
Trouble
ON
Blink ON/OFF
OFF
OFF
ON
4.5V
4.5V
4.5V
