KNF-700G Underground Multi Parameter Gas Detection Terminal 4G IP68 TDLAS Methane H2S O2

KNF-700 / KNF-700G Underground Multi-Parameter Gas Detection Terminal

The KNF-700 and KNF-700G are integrated underground gas detection terminals developed for sewer and inspection well (manhole) monitoring, including odor monitoring in drainage networks. Methane concentration is measured by tunable diode laser absorption spectroscopy (TDLAS), which delivers excellent selectivity and long-term stability without consumable sensors. Hydrogen sulfide, carbon monoxide, oxygen, barometric pressure, temperature and liquid level are measured simultaneously in one compact IP68 housing.

Main Features

• 3.6 V large-capacity lithium battery, more than 2 years of continuous operation in factory mode.
• TDLAS tunable laser absorption spectroscopy for methane, with good selectivity and no cross interference.
• Simultaneous detection of H2S, CO, O2, temperature and barometric pressure.
• Optional liquid level measurement, maximum error less than 5 mm.
• External expansion interface for additional sensing functions.
• Designed for inspection well installation, not affected by humid air.
• Air pump sampling, not afraid of soaking water.
• 4G wireless transmission with strong adaptability to underground signal conditions.
• GPS and Beidou positioning (wireless version).
• Three years of free data traffic included.
• Default sampling once every 30 minutes and data upload once every 24 hours; 50 events per year with successful transmission and no network failure.
• Immediate data upload when the alarm threshold is exceeded (no more than 3 times per day).
• Explosion-proof design, IP68 protection and corrosion resistance.

Electrical Parameters

Detection Parameters

Installation

The terminal is installed 15 ~ 20 cm below the ground. The mounting frame is fixed on the shaft wall with expansion screws or cement nails, and the terminal is placed on the mounting frame. Where signal quality is good, the antenna can be installed at the well exit about 15 ~ 20 cm away from the surface. Where the field signal is weak, a split antenna can be configured and the equipment antenna buried in a shallow ground slot (18 cm length, 7 cm width, 3 cm depth) covered with cement or asphalt to restore the road surface. A rotating arm is available for liquid level measurement when the radar path is blocked.

Quality Assurance

The warranty period is one year from the date of delivery. Products repaired or replaced during the warranty period remain covered only for the unexpired time remaining in the original warranty period. Normal wear and tear, defects caused by abuse, accident, misuse, modification, or failure to install, maintain and use the product according to the manual are outside the warranty scope.