Model: RTU5023 Name: GSM SMS Temperature Humidity Alarm Keyword: GSM Temperature Alarm, SMS Temperature Alarm, Temperature SMS Alarm, Temperature Alarm, Remote Temperature Monitoring, Remote Temperature Alert.Temperature Monitor, Temperature Sensor with SMS Alarm, SMS Temperature Monitoring.Humidity Alarm, Humidity SMS Notification, GSM Environment Alarm. The GSM SMS Environment Alarm is special for remotely monitoring onsite temperature, humidity, power status through wireless GSM Network. When the temperature, humidity, power voltage exceed high threshold or low threshold value, will send SMS alert to upto 10 preset mobile phone immediately. Just dial from Authorized User number, the GSM Environment Alarm will reject at the first ??Ring?�, no communication cost, and then return the current temperature, humidity, power status or voltage. Moreover, it can report onsite environment interval or daily. The GSM Environment Alarm can be used for solar power monitoring, DC power voltage monitoring, temperature monitoring, humidity monitoring, Class Room, Public Room, Waiting Room, Hospital, Stations, Fresh Food Warehouse, Office, Meeting Room, Laboratory, Library and anywhere that need monitoring temperature or control temperature in expected range. Mainly Features : 1. Can be operated from anywhere, no distance limitation; 2. No call charges for inquiry. the GSM Environment Alarm rejects the call from authorized number then return onsite temperature, humidity, and power voltage on the first 'ring'; 3. Multiple applications. (temperature, humidity, power status, solar panel, dc voltage); 4. Up to 10 authorized phone numbers, 5 can be used to receive call or SMS,and 5 can be used to call and SMS while alarm occurrence; 5.One Temperature & Humidity sensor input, measures temperatures from -40-80°C,0.5°C accuracy, Relative Humidity from 0-99RH%, accuracy is 3%; 6.External AC Power status monitoring, AC On/OFF will send SMS to authorized phone numbers; 7.Inbuilt MCU monitoring the DC input Voltage value, measure range is 9-24VDC, no need additional sensor to save cost; 8.Timer Report??Can setup every x hours automatically send its status/Value to the authorized numbers; 9.Support remotely read historic data via SMS; 10.Rechargeable Backup Battery inside can last 8hours; 11.Secure - Using caller ID and password for identification, unknown callers are ignored; 12.Programmable by SMS Commands or APPs with password protection; 13.Based on GSM Network, applied to many applications.