Specification of Indoor Temperature Humidity TransmitterLFH21

Technical parameter

LEFOO Indoor Temperature and Humidity Transmitter LFH21
Relative Humidity
Sensor	Digital type
Range	0%~100%RH
Output	RS485/Modbus,0~10VDC
Accuracy	±3%@ 20℃ & 20~80%RH
Response time	≤10s (20℃, slow flow air)
Temperature
Sensor	Digital or passive thermal resistor, details refer to selection table
Range	0~50℃, -20~60℃, etc
Output Signal	RS485/Modbus,0-10VDC
Thermal Resistance	Details in selection table and thermal resistance graduation table
Accuracy	Digital sensor: ±0.3℃@20℃, See table below ; Passive thermal resistance: typical ±0.2~0.4℃@25℃, refer to selection table
Power Supply	RS485:15-35VDC/24VAC±20%	Voltage:15-35VDC/24VAC±20%
	Note: when RS485 and voltage type uses AC power supply, an isolation transformer is required Output load
Output Load	≥10kΩ(voltage output)
Display Accuracy	0.1℃,0.1%RH
Display and buttons	LCD display and keys with unit display and backlight
Alarm Function	1xBUZZER,1xLED
Relay	2 x SPST, 3A / 30VDC, 3A / 250VAC
Shell Material	PC
Working Environment	-20~60℃, 5%-95%RH (Non-condensing)
Protection Grade	IP30