Compliant with Ministry of Economy, Trade and Industry "Guidelines for Selection of Carbon Dioxide Concentration Measuring Instruments" High-precision optical NDIR dual beam sensor, built-in CO2 concentration correction (calibration) function Specification table Standard type Data logger built-in type Standard type （ type NMA-VRC-IIM RS485 Modbus） Data logger built-in type Half size （AC type） manufacturer's recommended retail price （DC24V type） manufacturer's recommended retail price（DC24V type） manufacturer's recommended retail price Control by RS485 Modbus RTU, relay output or proportional output Control dampers by proportional output Control of ventilation equipment by ON/OFF Optical NDIR （non-dispersive infrared absorption） dual beam sensor Measurement method Temperature dependent Large value of ±0.2% or ±2 ppm per 1°（25℃ standard） C 0.13% per 1mmHg with altitude adjustment function （Factory setting is 0m） Response time Correction calibration） （ function Manual correction （calibration） （0-3,000 ppm） CO2: Within ±75 ppm or ±5% larger value Accuracy Usage conditions Temperature: 0-50℃; Humidity: 95% or less, No condensation （environment with airflow of 0.1m/s or more is recommended） Measurement range Measurement interval Relay setting range Temperature: 0-50℃; Humidity: 95% or less. No condensation 5 seconds （Update Period） MAX 2A （DC30V or AC250V） 1 contact, normally open.ON when AL2 is exceeded, then OFF when AL1 is exceeded . （reverse setting is also possible） （SMA-VRC-III only） *Relay output selectable by CO2 or temperature Relay output Current output 4-20mA: CO2 or temperature (opposite to voltage value) 0-10V: CO2 or temperature (opposite to current value) Analog output Voltage output Output width Digital output RS485 Modbus RTU （NMA-VRC-IIM/SMA-VRC-III only） Record CO2 concentration, temperature and humidit y ever y 5 seconds to MicroSD card （included） . About 2 years with 1GB （NMA-PR-RD/NMA-VRC-IID only） Data recording LCD display All display / CO2 concentration only display / non-display selectable （switchable among 3 patterns） All display/CO2 concentration only display/temperature and humidity only display/non-display selectable switchable among 4 patterns） （ 3-color switchable lighting depending on CO2 concentration （non-display selectable） Sounds 4 times at ALARM1 or higher; sounds 8 times at ALARM2 or higher. With mute function Power supply Power consumption Life expectancy of Sensor Product warranty period Power switch （OFF/AUTO/ON） Retaining screw Wiring space （notch possible） 9×16 size Power switch （OFF/AUTO/ON） Top surface Power outlet for maintenance Retaining screw Gas inlet MicroUSB socket * Retaining screw Retaining screw In the case of data logger built-in type *The bottom surface varies depending on the models MicroSD card slot Bottom surface Power inlet for maintenance 7.5 Gas inlet （used for calibration） 7.5 Communication hole for wiring The display and operation buttons/switches can be covered with