Often referred to as Gear Tooth Sensors because they record the movement of ferrous targets, typically gear teeth, passing through a magnetic field. Magnetic Sensors Corporation offers four basic types of gear tooth sensors:

Analog Variable Reluctance (VR) Speed Sensors - Passive Sensors. Require no outside power source. Respond to collapse of magnetic field caused be interruption by ferrous gear teeth. VR sensors have the capacity to measure very high speeds, high reliability, long life, and economy. Can be configured for use in very high temperatures.

Digital Variable Reluctance (DVR) Speed Sensors - Active Sensors. On-board electronics condition sine wave output to produce a digital, square wave signal.

Hall Effect Speed (HE)Sensors - Active Sensors. Zero speed, non-contact sensors measure magnetic field distortion, providing precise measurements of movement as slow as zero IPS.

Quadrature Speed & Direction Sensors - Active Sensors. Hall effect sensors with separate output to measure rotation or linear surface speed and direction.

MSC Speed Sensors are available in all standard configurations, sizes from .150 barrel-type to 3/4". Metric from 12mm to 22mm.

Passive Speed Sensor From Smith Systems:

075-003- Magna -Tran® Model 7500 Series Standard Passive Speed Sensor ( 3/4 - 16 UNF-2A)

• Flow meters
• Pump shaft speed
• Transmission speed
• Multiple engine synchronization
• Engine RPM
• Feedback for speed control
• Over/under speed
• Crankshaft position/engine timing
• Wheel speed
• Auto racing

Please use the links to he right for additional information, specifications and Drawings or to ask a question or to request a quotation for your application.

To download our full Standard and Custom Catalog please use this link: http://www.smith-systems-inc.com/products_and_services/online_catalog/online_catalog.pdf

Why Smith Systems?

Mission Statement

Smith Systems, Inc.is an innovative manufacturer of state-of-the-art sensing products serving the world marketplace, dedicated to customer satisfaction, employee growth and community enhancement

Customer Satisfaction

Smith Systems, Inc.is firmly committed to the philosophy that quality and reliability make a product cost effective. To that end, Smith Systems, Inc.is not only concerned with customer wants, but customer needs and customer satisfaction. We are committed to service by providing the most reliable product possible.

High output, High Sensitivity Passive speed sensors convert mechanical motion to A/C voltage without an external power source. These self-contained magnetic sensors produce a magnetic field which, when in the proximity of ferrous objects in motion, generate a voltage. When a magnetic sensor is mounted in the proximity of a ferrous metal target, such as gear teeth on a rotating shaft, the voltage output frequency is directly proportional to the rotational speed of the target. Typically, lower in maintenance and operating costs than mechanical devices, these sensors have no switches to wear out, no rotating couplings to snap or bulbs to burn out. Magna-Tran® speed sensors are available in a variety of housing configurations and terminations. These self-generating sensors are available can supply signal outputs as high as 375 Volts Peak to Peak, depending on the application. These passive sensors are designed to accommodate a broad spectrum of temperatures ranging from -65°F to 450°F and are resistant to oil, dirt and moisture, and pass MIL-STD-202, Method 204, Condition D vibration tests.

Magnetic Sensors Corporation

Analog Variable Reluctance (VR) Speed Sensors - Passive Sensors. Require no outside power source. The sensor generates a sinusoidal output voltage proportional to target speed and air gap. Analog signal is generated in response to fluctuation in magnetic field resulting from interruption by ferrous targets. VR sensors have the capacity to measure very high speeds, high reliability, long life, and economy. Can be configured for use in very high temperatures.

Effective target speeds range from 20 inches per second (IPS) to several hundred IPS, indicated by signal frequency and/or voltage. The output voltage, depending on air gap and the target surface speed, ranges from a few millivolts at the slowest target surface speed to several volts at the highest target speed as depicted graphically on the catalog data sheets.

Contrinex has developed the 'Series E' range of miniature sensors that can withstand up to 300psi continuously on the front face. Available in 4mm, M5, 6.5mm and M8 sizes, these devices can be embedded in pressurized systems to detect moving elements or targets.

A typical application would be gear tooth detection for speed or position control in gearboxes, dispensing and water pumps and similar equipment. In addition to its high degree of sealing, this range has a very fast 5KHz, switched output that can be essential when counting small gear teeth reliably.

Another application is in pneumatic systems to detect piston positions within cylinders. Where cylinders are subject to high vibration and shock, conventional reed switch feedback is often not suitable while the 'Series E' sensor provides a stable and positive control feedback in the most aggressive vibration conditions.

The sensing face of the 'Series E' sensors are made from tough sapphire on the 4mm and M5 versions and from thick ceramic on the 6.5mm and M8 models. This is because the conventional plastic front face found on many sensors of this type is vulnerable and unsuitable in applications where the sensor is in continuous contact with fluids and lubricants.

The housings are precision machined from tough AISI 303 stainless steel that is resistant to most corrosive liquids and media. High flexibility polyurethane (PUR) cables are fitted to all models. PUR is resistant to most oils and remains flexible even at low temperatures, preventing cracking or splitting that can lead to system failure.

The rear of the sensors are IP68 sealed, they have a wide voltage supply range of 10 to 30VDC, and will switch an output current of 200mA. The sensing range is stable from -25°C to +70°C, and they are short circuit and inverse polarity proof and overload protected.

Hall effect, zero speed non-contact sensors provide a TTL compatible constant amplitude output over target speed ranges from 0 Hz to 50,000 Hz with air gaps up to .125". · True Zero Speed Sensing. · Wide Operating Voltage Range from 5 VDC to 24 VDC. · Open Collector Output with Sinking Currents to 35 MA. · Operating Temperature Range to 150°C.

The Motion Sensors (MSI) HD series of sensors is based on Hall Effect sensor technology, which can sense a change in target motion from true zero to 20 KHz.

These sensors are dual channel versions of MSI's H series or HM series of sensors and offer two channels of output.

HD sensors based on the HM series require that the target be a magnet, such as magnets embedded in gear teeth, blade tips, or around a disc. They must be oriented to the direction of the target movement and can be set to sense both north and south oriented magnets or only north or south respectively. Air gap distances can be as much as 0.200" to 0.250" away, depending on target shape and magnetic field strength.

HD sensors based on the H series incorporate a magnet within the sensor, enabling them to sense ferrous metal as well as magnet targets. Maximum air gap sensing distances are typically 0.100" and these sensors can be optimized to detect fine as well as large pitch targets. As with sensors based upon the HM series, they must be oriented to the direction of target movement to work effectively. The output frequency of HD sensors has a square pulse waveform (digital) that directly relates to the number of turbine blades, gear teeth, etc. that have been sensed. These pulses, in turn, can be correlated to determine flow rate, RPM, or velocity.

Product Specifications

HD series Hall Effect sensors are manufactured on a custom basis to meet the specifications and requirements of a particular application. MSI can make custom dual channel Hall Effect sensors in customer-specified lengths, diameters, configurations, mounting threads (e.g., metric) as well as with different operating specifications and options like pigtail leads, NPT threads for explosion proof applications, etc. Please contact MSI and they will be happy to make a product that meets your specifications.