Features Measures indoor PM2.5, PM10, CO2 concentra-tion, Temperature and Humidity every 60 seco-nds when powered with USB or detecting every 10 minutes when powered with batteries only.USB power connection for indoor use onlyCO2 value calibration function available on the devicePM2.5 value Calibration function available whenpaired with the WiFi Gateway/GW1100/HP2551/HP3500 /HP3501Long wireless range, up to 330 feet (100 meters) in open areas Features Measures indoor PM2.5, PM10, CO2 concentra-tion, Temperature and Humidity every 60 seco-nds when powered with USB or detecting every 10 minutes when powered with batteries only.USB power connection for indoor use onlyCO2 value calibration function available on the devicePM2.5 value Calibration function available whenpaired with the WiFi Gateway/GW1100/HP2551/HP3500 /HP3501Long wireless range, up to 330 feet (100 meters) in open areas When paired with the GW1100 Wi-Fi Gateway Monitor live sensor data on the Live Data page of the WS View Plus/ Ecowitt App (requires the Wi-Fi gateway and your phone using the same Wi-Fi network)Displays current PM2.5 / PM10 concentration/AQI and 24H AQI and air quality level index on the Live Data page of the WS View Plus/ Ecowitt AppDisplays current CO2 concentration and 24H average CO2 concentration on the Live Data page of the WS View Plus/ Ecowitt AppDisplays temperature and humidity data where the sensor locatedCalibration function available for PM2.5 value How to Pair with GW1100 Wi-Fi Gateway If the WiFi Gateway/GW1100 has been in operation, and you have never had any WH45 sensor setup before, just power up the sensor and the WiFi Gateway/GW1100 will pick sensor data automatically.If a WH45 sensor has been hooked on the WiFi Gateway/GW1100 before, and you have a new sensor to replace the old one, just power off the old sensor and power on the new sensor, open the APP: WS View Plus/ Ecowitt App, tap the device and go to sensor ID page, locate the WH45 sensor, select “Register”, then the gateway will erase the previous registered sensor and have the new sensor paired. When paired with the GW1100 Wi-Fi Gateway Monitor live sensor data on the Live Data page of the WS View Plus/ Ecowitt App (requires the Wi-Fi gateway and your phone using the same Wi-Fi network)Displays current PM2.5 / PM10 concentration/AQI and 24H AQI and air quality level index on the Live Data page of the WS View Plus/ Ecowitt AppDisplays current CO2 concentration and 24H average CO2 concentration on the Live Data page of the WS View Plus/ Ecowitt AppDisplays temperature and humidity data where the sensor locatedCalibration function available for PM2.5 value How to Pair with GW1100 Wi-Fi Gateway If the WiFi Gateway/GW1100 has been in operation, and you have never had any WH45 sensor setup before, just power up the sensor and the WiFi Gateway/GW1100 will pick sensor data automatically.If a WH45 sensor has been hooked on the WiFi Gateway/GW1100 before, and you have a new sensor to replace the old one, just power off the old sensor and power on the new sensor, open the APP: WS View Plus/ Ecowitt App, tap the device and go to sensor ID page, locate the WH45 sensor, select “Register”, then the gateway will erase the previous registered sensor and have the new sensor paired. When Paired with a Weather Station Console (HP2551/HP3500/HP3501) The PM2.5, PM10 and CO2 data automatically scrolls displaying on the screen every 5 seconds Calibration function available for PM2.5 value When Paired with a Weather Station Console (HP2551/HP3500/HP3501) The PM2.5, PM10 and CO2 data automatically scrolls displaying on the screen every 5 seconds Calibration function available for PM2.5 value When Uploaded to Ecowitt Weather Server View current sensor data & history records & graph on the websiteSet and receive email alerts from the server when alarm condition set under your account.Remote monitoring with smart phone, laptop, or computer by visiting the website When Uploaded to Ecowitt Weather Server View current sensor data & history records & graph on the websiteSet and receive email alerts from the server when alarm condition set under your account.Remote monitoring with smart phone, laptop, or computer by visiting the website Sensor Calibration CO₂ There is an easy way to find the CO₂ sensor is drifted or not: put the sensor in outdoor open air locations, away from any combustion exhausts, wait for 30 minutes, you should see the CO₂ reading is 420ppm +/-10. If it is far from this reading, you can wait for some more time, and test it during night to confirm. Once it is confirmed, you can open the back housing, and use a clipper pin to press the Calibrate button as below figure shows, leave it for 30s, and the reading will be shifted back to 420ppm.Note : If you have a reliable source to calibrate the CO₂ data, you may calibrate the offset on the web page (ecowitt.net) or the WS View Plus/ Ecowitt App(for the WiFi Gateway/GW1100/WN1900 only), or the HP2551 /HP3500/HP3501 console. If the deviation is large, it's recommended to place the sensor in an outdoor ventilated place for 30 minutes before calibrating. PM2.5 It is not possible to calibrate on the sensor side, and you can calibrate through the web page (ecowitt.net) or WS View Plus/ Ecowitt App when paired with the WiFi GW1100 Wi-Fi gateway or on the console when paired with HP2551/HP3500/HP3501, which saves the offset value on the gateway side before sending data to ecowitt.net server. However if PM2.5 data is persistently low, it can be that there is a spider net going inside the sensor. So please clean the sensor from time to time to see if there is any sign of spider penetration. Note : If the battery level is lower than 4 bars, calibration is prohibited. When the led light on the sensor is steady for 3 seconds, it indicates that calibration is prohibited. Sensor Calibration CO₂ There is an easy way to find the CO₂ sensor is drifted or not: put the sensor in outdoor open air locations, away from any combustion exhausts, wait for 30 minutes, you should see the CO₂ reading is 420ppm +/-10. If it is far from this reading, you can wait for some more time, and test it during night to confirm. Once it is confirmed, you can open the back housing, and use a clipper pin to press the Calibrate button as below figure shows, leave it for 30s, and the reading will be shifted back to 420ppm.Note : If you have a reliable source to calibrate the CO₂ data, you may calibrate the offset on the web page (ecowitt.net) or the WS View Plus/ Ecowitt App(for the WiFi Gateway/GW1100/WN1900 only), or the HP2551 /HP3500/HP3501 console. If the deviation is large, it's recommended to place the sensor in an outdoor ventilated place for 30 minutes before calibrating. PM2.5 It is not possible to calibrate on the sensor side, and you can calibrate through the web page (ecowitt.net) or WS View Plus/ Ecowitt App when paired with the WiFi GW1100 Wi-Fi gateway or on the console when paired with HP2551/HP3500/HP3501, which saves the offset value on the gateway side before sending data to ecowitt.net server. However if PM2.5 data is persistently low, it can be that there is a spider net going inside the sensor. So please clean the sensor from time to time to see if there is any sign of spider penetration. Note : If the battery level is lower than 4 bars, calibration is prohibited. When the led light on the sensor is steady for 3 seconds, it indicates that calibration is prohibited. Specification PM 2.5 - Measurement Range 0~999ug/m³ PM 2.5 - Measurement Accuracy When 0-100ug/m³, ±10ug/m³. When100-1000ug/m³, ±10% PM 2.5 - Resolution 1ug/m³ PM 10 - Measurement Range 0~999ug/m³ PM 10 - Measurement Accuracy When 0-100ug/m³, ±25ug/m³. When 100-1000ug/m³, ±25% PM 10 - Resolution 1ug/m³ CO₂ - Measurement Range 0- 40000 ppm CO₂ - Measurement Accuracy When 400-10000ppm, ± ( 30ppm ±3% ) CO₂ - Resolution 1ppm Temperature-Measurement Range -40°C ~ 60°C ( -40°F ~ 140°F ) Temperature - Accuracy ± 1°C, or ± 2°F Temperature - Resolution 0.1°C, or 0.1°F Humidity - Measurement Range 1%~99% Humidity- Measurement Accuracy ± 5% Humidity - Resolution 1% Sensor Reporting Interval 1 minute (10 minutes when only powered by batteries) Package Content 1 × 5-In-1 Detection Sensor (PM2.5 / PM10 / /CO2 / Temperature / Humidity)1 × USB Cable1 × User Manual Package Content 1 × 5-In-1 Detection Sensor (PM2.5 / PM10 / /CO2 / Temperature / Humidity)1 × USB Cable1 × User Manual