AI-TEK 70085-1010-028 70085 Series Passive Speed Sensors

The AI-TEK 70085-1010-028 belongs to the renowned 70085 Series of passive speed sensors manufactured by AI-Tek Instruments (formerly Airpax), a brand synonymous with high-reliability speed measurement solutions for over decades . These sensors utilize variable reluctance technology to convert rotational motion into electrical signals without requiring external power, making them ideal for permanent installation in critical industrial machinery .

As a variable reluctance sensor, the 70085-1010-028 generates a sinusoidal voltage output as ferrous targets—such as gear teeth, keyways, or slots—pass the sensor's pole piece. The frequency of this signal is directly proportional to the rotational speed, while the voltage amplitude increases with target velocity . This self-generating principle ensures long-term reliability in demanding environments.

Key Specifications and Performance Data

The AI-TEK 70085-1010-028 is engineered for high-output performance and environmental resilience. Below are its critical specifications based on manufacturer data :

Specification Value

Thread Size M10 (5/8-18 mounting thread)

Thread Length (A) 36.50 mm (1.44 inches)

Output Voltage (Standard) 75 V peak-to-peak (P-P)

Output Voltage (Guaranteed) 21.5 V peak-to-peak (P-P)

DC Resistance 210 ohms maximum

Typical Inductance 50 to 95 mH (reference)

Operating Temperature -73°C to +107°C (-99°F to +225°F)

Frequency Response 1 Hz to 50 kHz

Environmental Protection IP67 (dust-tight and waterproof)

Output Polarity Pin "B" positive

Lead Length 500 mm (standard)

The 75V peak-to-peak output ensures strong signal integrity even over long cable runs or in electrically noisy environments, while the guaranteed minimum of 21.5V at the specified test point provides a reliable safety margin for control system triggering .

Superior Environmental Durability

One of the standout features of the 70085-1010-028 is its ability to perform under extreme conditions. With an operating range from -73°C to +107°C, this sensor is suitable for both cryogenic applications and high-temperature industrial processes . The storage temperature extends even further, from -80°C to +120°C.

The IP67 rating confirms complete protection against dust ingress and temporary submersion in water, making the sensor suitable for outdoor installations, washdown environments, and locations exposed to coolant or lubricants . Additionally, the sensor withstands vibration up to 10 g (rms) and shock up to 500 g for 1 millisecond, ensuring reliable operation on reciprocating compressors, turbines, and heavy rotating equipment .