Turbine Interface Accessories

Magnetic Pickups & Gears

Description

Passive Magnetic Speed sensors are simple, rugged devices that don’t require any external power to operate. A permanent magnet in the sensor establishes a fixed magnetic field and passing a ferrous metal target (gear) near the sensor’s pole piece (sensing area) changes the flux lines of the magnetic field, dynamically changing its strength.

This change in magnetic field strength induces a current into a coil winding which is attached to the pickups output terminals. The output signal of the sensor is an ac voltage that varies in amplitude and wave frequency as the speed of the monitored device changes, and is usually expressed in peak to peak voltage (Vp-p).

One complete waveform (cycle) occurs as each target passes the sensor’s pole piece. If a standard gear were used as a target, this output signal would resemble a sine wave if viewed on an oscilloscope.

High Output sensors are designed for use in applications where higher output voltages are needed. They perform best at low to medium speeds with medium to high impedance loads. Front-End Sealed versions are available for use where the sensor is exposed to fluids, lubricants or adverse environmental conditions.

Applications

  • Engine RPM (revolutions per minute) measurement on aircraft, automobiles, boats, buses, trucks and rail vehicles
  • Process speed measurement on food, textile, paper, woodworking, printing, tobacco and pharmaceutical industry machinery
  • Motor speed measurement of electrical generating equipment
  • Speed measurement of pumps, blowers, mixers, exhaust and ventilating fans
  • Flow measurement on turbine meters
  • Gear speed measurement

Features

  • Self-powered operation
  • Direct conversion of actuator speed to output frequency
  • Simple installation, No moving parts
  • Designed for use over a wide range of speeds
  • Adaptable to a wide variety of configurations
  • Customized VRS products for unique speed sensing applications
  • Housing materials/styles: stainless steel threaded or smooth
  • Output voltages: 8 Vp-p to 190 Vp-p

Standard Passive Speed Pick-Ups

Common Specifications

Feature Description
Output Voltage (Peak to Peak) Min. 190 Vp-p
Pole Piece Shape and Size Round, 2.69 mm [0.106 in] Dia.
Operating Temperature -55 °C to 120 °C [-67 °F to 250 °F]
Gear Pitch Range 24 DP (Module 1.06) or Coarser
Operating Frequency 15 kHz
Inductance 450 mH
Coil Resistance 910 Ohm to 1200 Ohm
Surface Speed 0.25 m/s [10 in/s]
Optimum Actuator 20 DP (Module 1.27) Ferrous Metal Gear
Mounting Thread 5/8-18 UNF-2A (M16 Metric Thread Available)
Vibration MIL-STD 202F, Method 204D
Material Stainless Steel Threaded
Termination MS3106 Connector

Models

Model Number 7121-0000 7125-0000 7131-0001
Description Std – 5/8-18 x 2.218″ (1.125″ threads) LR – 5/8-18 x 5.093″ (4.00″ threads) Std – 5/8-18 x 6.107″ (5″ threads)
Diameter 15.9 mm [0.625 in] 15.9 mm [0.625 in] 15.9 mm [0.625 in]
Housing Length 56 mm [2.20 in] 130 mm [5.10 in] 156 mm [6.10 in]
Weight 70 g [2.5 oz] 98 g [3.5 oz] 128 g [4.5 oz]

Explosion Proof Passive Speed Pick-Ups

Common Specifications

Feature Description
Output Voltage (Peak to Peak) Min. 60 Vp-p
Pole Piece Shape and Size 4.75 mm [0.187 in] Diameter
Operating Temperature -73 °C to 93 °C [-100 °F to 200 °F]
Gear Pitch Range 12 DP (Module 2.11) or Coarser
Operating Frequency 40 kHz
Inductance 115 mH
Coil Resistance 191 Ohm to 280 Ohm
Surface Speed 0.38 m/s [15 in/s]
Optimum Actuator 8 DP (Module 3.17) Ferrous Metal Gear
Mounting Thread 3/4-20 UNEF-2A
Vibration MIL-STD 202F, Method 204D
Material Stainless Steel Threaded
Termination 24 AWG PVC-Insulated Leads, 3000 mm [120 in]
Test Condition Specifications: Surface Speed = 25 m/s [1000 in/s], Gear = 8 DP (Module 1.27), Air Gap = 0.127 mm [0.005 in], Load Resistance = 100 kOhm

Models

Model Number 7120-0000 7130-0000 7131-0503 7131-0000
Description Std – 3/4-20 x 3.125″ (1.875″ threads) LR – 3/4-20 x 4.75″ (3.5″ threads) 5/8-18 x 3.050″ (1.8″ threads) 5/8-18 x 9.75″ (8.5″ threads)
Diameter 19.5 mm [0.750 in] 19.5 mm [0.750 in] 15.9 mm [0.625 in] 15.9 mm [0.625 in]
Housing Length 78 mm [3.05 in] 122 mm [4.80 in] 78 mm [3.05 in] 122 mm [4.80 in]
Weight 294 g [10.5 oz] 322 g [11.5 oz] 280 g [9.0 oz] 366 g [10.0 oz]

High Output Speed Pick-Ups

Common Specifications

Feature Description
Output Voltage (Peak to Peak) Min. 9.2 Vp-p
Operating Temperature -65 °F to 220 °F
Inductance 87 mH Typical
Coil Resistance 190 Ohm to 210 Ohm
Mounting Thread 5/8-18 UNF-2A
Material Stainless Steel Threaded
Thread Length 4.0 in.
Termination MS3106 Connector
Test Condition Specifications: 276 Hz, 8 pitch Gear, 0.016 Gap., And 270 Ohm Load

Models

Model Number 7131-0004
Description HO – 5/8-18 x 5.093″ (4.0″ threads)
Diameter 0.140 in
Housing Length 5.093 in
Weight 128 g [4.5 oz]