IAQ Indoor Air Quality Controller and Indicator
CO2, Temperature, Humidity, Dew Point

  • CO2, Temp, RH, Dew Point
  • LCD Display
  • LED Indicators
  • Analog Outputs
  • Relay Outputs
  • User settable alarms
  • Modbus RS485
  • Free software
  • Custom configurations on request
  • PDF Data Sheet

The instruments of the series HD45 and HD46 are transmitters, indicators and regulators, to monitor and control:
• Relative humidity (RH)
• Ambient temperature (T)
• Carbon dioxide (CO2)
• Dew point temperature (DP, calculated measurement)
They are suitable for monitoring indoor air quality. Typical applications would be air quality in institutional buildings, factories and workplaces where there are large gatherings of people (schools, hospitals, auditoriums, cafeterias, etc.) The instrument facilitates the automatic adjustment of air conditioning (temperature and humidity) and ventilation (changes air/hour) in order to achieve good air quality according to the ASHRAE and IMC standards as well as promoting energy savings. The measurement of RH (Relative Humidity) is done with a capacitive sensor. In models HD46 ... the relative humidity and temperature sensor with their calibration data are contained within an easily replaceable module. The instrument can also calculate the dew point. The temperature T is measured with a high precision NTC sensor.The measurement of CO2 (carbon dioxide) is obtained with a special infrared sensor (NDIR technology: Non-Dispersive Infrared Technology), A protective membrane, protects the sensor from dust and weather. The instruments are factory calibrated and require no further adjustment by the installer

The instruments are wall mounted indicator panels with the sensors installed inside the housing. The LCD display allows simultaneous viewing of all values measured. The operation of the relay is very versatile, having modes of activation above and below the threshold, and single or double threshold modes. The thresholds are configurable by the user throughout the measurement range. All the functions of the instrument can be configured quickly and intuitively through a PC. The instruments are easy to use and offer many configuration possibilities They are supplied with a standard configuration that makes them ready to use out of the box. The HD46... can be equipped with keyboard that allows you to easily configure the instrument even without a PC connection. The models having a keypad are fitted with backlit display, activated by the touch of a button. Models of the series HD45... with relay have a switch that allows quick selection of the threshold between a set of preset values. All models include the continous logging so that data can be transferred to a PC. A circular memory routine always holds the latest 2304 readings. The instruments work with 24Vac or 15...35Vdc power supply

Parameter RH Temperature CO2
Sensor Capacitive NTC 10kΩ Dual Wavelength NDIR
Range 0...100 % RH-40...+85°C Dew point Td -30...+85°C (-22...+185°F) 0-5000ppm
Accuracy ±2.5%RH (0..90%RH)±2%RH (elsewhere) for T=15...35°C±(1.5+1.5% of the measure)%RH for T=40...+80°CFor the dew point please see the relevant tabl ±0.2°C ±0.15% of the measured value within 0...70°C±0.3°C ±0.15% of the measured value within -30...0°C and 70...85°C
(for models with 4-20mA ±0.5°C ±0.15% of the measured value within -30°C...+85°C)
±(50ppm+3% of the measured value) @ 20°C and 1013hPa
Resolution 0.1% 0.1°C 1 ppm
Response time <20 sec.(air speed = 2m/sec and stable temperature <30 sec. (air speed = 2m/sec) <120 sec.(air speed = 2m/sec and stable temperature
Long Term Stability 1%/year 0.1°C/year 5% of the measured value /5year
Temperature Dependence 2% on the whole temperature range - 0.1%f.s./°C
Hysteresis and repeatability 1% RH - -

General Specifications

Measuring Frequency 1 sample every 3 seconds
Storage Capacity

2304 Records

Storage Interval Selectable within 30s, 1m, and 5mThe stored values represent the average values of samples collected every 3 seconds in selected storage interval
Serial Output Selectable within 30s, 1m, and 5m
The stored values represent the average values of samples collected every 3 seconds in selected storage interval
Analogue Output 0...10Vdc (RL > 10kΩ) (only HD45...V...and HD46...V)
11Vdc outside the measuring range
4÷20mA (RLMAX = 400Ω) (only HD45_A and HD46_A)
22mA out of the measuring range
Active current outpu
Relay Output Two-state (only HD45...R and HD46...R)
Contact: max 1A @ 30Vdc resistive load
Power Supply 24Vac ± 10% (50...60Hz) or 15...35Vdc
Power Consumption 100 mW (except of the models with current output)
400 mW (for the models with current outpu
Stabilizing Time 15 m
Working temperature 0°C -50°C
Working Humidity 0-90%RH non condensing
Protection class IP30
Case Dimensions 80 x 80 x 30 mm (HD45.17...)
80 x 80 x 34 mm (HD45.B... and HD45.7B...)
120 x 80 x 30 mm (HD46.17...)
120 x 80 x 34 mm (HD46.17B...
weight 30 g

Ordering Information

Part No. Example Configurations - go to the store link to configure other options Price each  
HD45BDR CO2 only with LCD Display and Relay $400.00
HD4517DA RH Temperature and Dew Point with Display and 4-20mA analog output $420.00  
HD457BS CO2 and Temperature with MODBUS-RTU Interface $395.00  
HD4617SRDT CO2, RH and temperature with MODBUS, relay, keypad interface and dispaly $763.00