The Land System 4 M1 is an industrial infrared thermometer designed for non-contact temperature measurement in harsh environments. The specific model 65071800C-L35-A50 with emissivity setting E=1 and Z4893 calibration identifier provides accurate readings for metals, ceramics, and other high-temperature surfaces. This device is part of Land Instruments’ System 4 range, known for reliability in process monitoring.
Temperature range: 0°C to 500°C (standard) or extended depending on optics. Spectral response: 8-14 µm (long-wave IR). Accuracy: ±1% of reading or ±1°C, whichever greater. Repeatability: ±0.5% of reading. Response time (95%): 240 ms. Emissivity setting E=1 (blackbody equivalent) – fixed at 1.00 or adjustable via external interface.
L35 optics designates a specific lens: distance-to-spot ratio 35:1. At 1000 mm distance, spot diameter is 28.6 mm. The device includes a through-lens sighting (laser or viewfinder). Minimum focus distance: 200 mm. The lens is protected by a replaceable window. A50 indicates a 50°C maximum ambient temperature for the electronics housing.
Analog output: 4-20 mA linearized, isolated. Loop-powered or externally powered (24V DC). Additionally, a TTL serial output (RS-232 compatible) for parameter setup. Alarm outputs: open collector (50 mA max). The 4-20 mA can be scaled over a subset of the temperature range (adjustable).
Power supply: 24V DC nominal (18-30V DC), consumption 100 mA + 4-20 mA loop. Operating temperature: sensor head -20°C to 70°C; electronics up to 50°C (A50). Protection: IP65 (NEMA 4X). Vibration: 3g (10-150Hz). The housing is stainless steel with a sealed cable gland. Weight: 0.9 kg.
This unit has emissivity fixed to 1.00, suitable for measuring blackbody-like surfaces or when using a reference emitter. For real surfaces with lower emissivity, an external controller can adjust the output using a linearization table. The Z4893 calibration certificate indicates traceable testing to NIST standards.

Used in steel mills, glass plants, cement kilns, and semiconductor manufacturing. The non-contact measurement is essential for moving materials or dangerous environments. The System 4 M1 can be connected to PLC analog input (4-20 mA) for closed-loop temperature control.
Mount the sensor with the supplied bracket. Clean lens regularly with optical cleaner. The air purge collar option prevents dust accumulation. Calibration interval: recommended 12 months. The device has no user-serviceable parts inside.
CE, RoHS, and UKCA. The sensor meets EN 61326-1 for EMC immunity. It is not explosion-proof but can be used in safe areas.
The Land System 4 M1 65071800C-L35-A50 E=1 Z4893 provides reliable, non-contact temperature measurement for industrial processes. Its 4-20 mA output simplifies integration with PLC or DCS systems.



