Technical Information for the CDM4161 CO 2 Module
Page
Basic Information and Specifications
<.2Structure and functions
Solid electrolyte CO 2 2Sensor's output signal voltage (CP3)........................................................2Variable resistor (VR1)...............................................................................2Thermistor signal output voltage (CP4).............
....................................2Concentration tting for system control (JP3, JP4)................................2Baline .4Input-output signal (CN1)....................................................................4Operation modes
5CO 2 concentration lower than .5CO 2 concetration exceeds 5Important Notice. (6)
a n I S O 9001 a n d 14001 c o m p a n y
IMPORTANT NOTE: OPERATING CONDITIONS IN WHICH FIGARO SENSORS ARE USED WILL VARY WITH EACH CUSTOMER’S SPECIFIC APPL ICATIONS. FIGARO STRONGL Y RECOMMENDS CONSUL TING OUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO SENSORS IN YOUR APPLICATION AND, IN PARTICUL AR, WHEN CUSTOMER’S TARGET GASES ARE NOT L ISTED HEREIN. FIGARO CANNOT ASSUME ANY RESPONSIBIL ITY FOR AN
Y USE OF ITS SENSORS IN A PRODUCT OR APPLICATION FOR WHICH SENSOR HAS NOT BEEN SPECIFICALLY TESTED BY FIGARO.
CDM4161 is a new unit which us TGS4161, Figaro's low-power consumption solid electrolyte CO
2nsor. Due to Figaro’s proprietary idea for signal processing with a microcomputer, no maintenance is required for this module. When compared with traditional CO 2nsor modules using IR nsors,Figaro’s CO 2 module is much more cost effective, making this module the ideal choice for indoor air quality control systems.
1. Basic Information
1-1 Features
* High lectivity to CO2
* Maintenance free
* Low power consumption
* Long life
* Compact size
* Pre-calibrated
* Low cost
1-2 Applications
* Indoor air quality control
* CO2 monitors
1-3 Specifications
The specifications of CDM4161 are contained in Table 1. Depending on the customer's target concentration range, Figaro offers two versions of this module as indicated in Table 1. Customized modules are available according to special requests from customers. Plea consult with Figaro.
1-4 Dimensions (e Fig. 1 below)
Fig. 1 - CDM4161 dimensions
Table 2 - CDM4161 pin designations of CN1 NOTE: CN1 should be MB5P-90S, mfg. by JST. Recommended receptacle for connector: 05JQ-BT, mfg. by JST.
u/m: mm 2. Structure and Functions
2-1 Solid electrolyte CO2 nsor TGS4161
The nsor changes its output voltage in respon to exposure to CO2 gas. The nsor should not be directly connected with low-input impedance equipment. To read nsor output, amplified voltage (CP3) should be ud. Plea refer to “TGS4161 Technical Information” for details as to the characteristics of the nsor.
2-2 Sensor's output signal voltage (CP3)
The nsor’s output can be read as an amplified voltage(as taken from the differential amplifier). Voltage should be read from this port.
2-3 Variable resistor (VR1)
This resistor is pre-calibrated at Figaro’s factory prior to shipment. Do not turn the screw—if this would be done, the module may not meet specifications.
2-4 Microprocessor
The microcomputer takes data and renews it once per cond. The processor calculates CO2 concentrations bad on the difference between current nsor output and a baline value (which reprents the nsor output value in fresh air).
2-5 Thermistor signal output voltage (CP4)
The thermistor’s output signal voltage, which is ud for compensation of the nsor’s temperature dependency, can be read at this port.
2-6 Concentration tting for control signal (JP3, JP4) Concentrations utilized for control signals (i.e. the control concentration) can be changed by modifying
Gas nsor
V
V CTRL
TRBL GND
Microcomputer
Fig. 2 - Circuit diagram of interface for circuit
Table 1 - Specifications
Note 1: Assumes benchmark is t accuractely at 400ppm of CO 2. This value does not contain long term drift.
Note 2: In this module, the CO 2concentration is calculated by measuring the relative change of nsor output at the measuring point from nsor output in clean air (assumed to be 400ppm of CO 2).
the ttings of JP3 and JP4 as shown in Table 3. The module is pre-t at Mode I before shipment.2-7 Baline ret switch
The baline value may be manually ret using this switch. When this switch is pushed, the nsor’s output at that moment is memorized as 400ppm of CO 2 (the baline value in fresh air). W
hen the switch is pushed during warm-up time (within the first two hours after the module is powered on), the baline voltage is read at that moment and the module immediately goes into operation mode.
Caution: If the baline ret switch is pushed while in a polluted environment where the actual CO 2concentration is higher than 400 ppm (ambient levels), the accuracy of readings may become adverly affected.
2-8 Input-output signal (CN1)
Plea refer to Table 4-Rated input and output voltages for rated values. Also plea refer to Fig. 2-Circuit diagram of interface for circuit.
2-8-1 Vin (Pin No. 1)
Regulated voltage should be input into this port. The nsor’s output may vary according to the nsor’s voltage dependency characteristics if the input voltage fluctuates. Plea refer to "TGS4161 Technical Information" for details.
2-8-2 Concentration output (Pin No. 2)
An analog voltage (CO 2 concentration/1000)
Table 4 - Rated input/output voltages
Table 3 - CDM4161 jumper pin ttings
corresponding to CO 2 concentration is output from this port.
2-8-3 Control signal output (Pin No. 3)
When CO 2 concentrations exceed the control concentration, output from this port will be “ON”.2-8-4 Trouble signal output (Pin No. 4)
This port will output “ON” in the following situations:
* when the nsor’s heater is broken
* when the connection for control concentration tting is broken 2-9 LEDs (refer to Table 5)
2-9-1 Green LED (LED 1)
The green L ED indicates the module’s power condition. It will be lit when the power is on. The LED blinks on and off during warm-up time (for the first two hours after power is turned on).
2-9-2 Yellow LED (LED 2)
The yellow L ED indicates a trouble condition. It
Table 5 - Signal output in operation mode
blinks on and off when trouble signal output is “ON”. 2-9-3 Red LED (LED 3)
The red LED indicates that CO2 concentration is over the control concentration level. It lights when control signal output is “ON”.
3. Operation modes
3-1 Warm up
The nsor 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) 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 CO2 concentration lower than calibrated
concentration
The green L ED will be on if the calculated CO2 concentration is lower than the calibrated concentration.
3-3 CO2 concentration exceeds calibrated concentration The red LED will be lit and the control signal output is turned “ON” if CO2 concentration exceeds the calibrated concentration.
The control signal output is turned to “OFF” and the LEDs will return to the status described in Item 2-9-2 when CO2 concentration drops to 90% of the calibrated concentration.
3-4 Trouble
Whenever a trouble situation occurs, such as heater breakage, the yellow LED blinks on and off and the TRBL signal is t to “ON.
4. Cautions
1) By assuming that the baline level reprents fresh air (400ppm of CO2), actual CO2 concentrations are calculated bad on the difference between the baline level and the current nsor output. As a result, the following cautions should be noted:
a) Accurate readings cannot be expected if an accurate baline could not be acquired.
b) The nsor should be expod to fresh air periodically to properly renew the baline level. Performance shown in the specifications cannot be achieved if the module was ud in an environment where CO2 concentrations incread 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 baline is acquired in fresh air. If the module is warmed up in an environment where CO2 concentration is higher than normal fresh air, the baline will reprent 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 baline 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 lif
e saving equipment, an alternative and cure measure for calculating CO2 concentration should be ud be ud 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) Plea apply a regulated voltage, otherwi the accurate reading cannot be expected. Application of excessive and/or rever voltage would cau damage to the module.
4) The nsor may deteriorate if it is stored without power in a high humidity environment for a long period of time. Plea keep the nsor in a humidity-proof bag with a desiccant if the nsor is to be stored
