temperature sensor for railway tunnel

LTE temperature sensor direct from Wanlin Fire Protection — 12-year factory experience, WL-HD903 fully certified UL 521/EN 54-5/CE/FCC/RoHS/REACH. Key specs: NB-IoT (LTE Cat-NB1), Fixed Temperature Sensor + NB-IoT Low-Power Module, 5-year replaceable battery (2x AA lithium). MOQ 100 units, 25-30 working days, OEM/ODM custom branding available. Serving 60+ co···

NB-IoT IoT heat detector direct from Wanlin Fire Protection — 12-year factory experience, WL-HD900 fully certified UL 521/EN 54-5/CE/FCC/RoHS/REACH. Key specs: 4G LTE Cat.1 + WiFi, Fixed Temperature + Rate-of-Rise Dual Sensor (57°C / 135°F), AC powered + 72h backup battery. MOQ 100 units, 25-30 working days, OEM/ODM custom branding available. Serving 60+ cou···

heat detector with remote configuration direct from Wanlin Fire Protection — 12-year factory experience, WL-HD904 fully certified UL 521/EN 54-5/CE/FCC/RoHS/REACH. Key specs: LoRaWAN 868/915MHz, Fixed Temperature Sensor + LoRaWAN Long-Range Module, 3-year replaceable battery (2x C lithium). MOQ 100 units, 25-30 working days, OEM/ODM custom branding available···