SLIM Tach SL85

SLIM Tach® SL85 Digital Tachometer

 SLIM Tach SL85
RIM Tach 1250

Quick Specs...

  • Only 1.250” thick, mounts directly onto 8.5” (180 C) face motor
  • Rugged, zero-speed, magnetoresistive sensing technology is unaffected by grease, salt water, dust, and other common contaminants
  • Up to 90° C operation

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Overview Industry/Application Specifications Related Info  

Overview / Design Principle:

The magnetoresistive sensor of the SLIM Tach® SL85 operates with an unparalleled immunity to grease, oil, salt water, dirt, fibers, and dust, thereby eliminating the need for sealing. It occupies only 1.250” of the motor shaft length, enabling the encoder and a flexible coupling or pulley to be mounted on the motor. The simple and sturdy design can be mounted in any attitude quickly and easily.

The sensor generates A and B phase quadrature signals and their complements ( —A & —B). The module provides transient and noise suppression, reverse polarity protection, and operates with DC power from +5 to +15 volts. A high power, complementary, line driver output assures clean, crisp signals over long cable lengths. The hardened encapsulated electronics of the SL85 make it especially resistant to heavy machine vibration and accidental impacts.

Mounting the SL85 onto the 8.5” (180 C) face of a motor is quick and easy with no adapter plates, bearings, or flexible coupling. Installation can be completed in seconds with no gap adjustments or special tools. The encoder can be removed then reinstalled just as easily. The latching industrial connector requires only a simple screw driver to install. To replace a module, simply remove four screws and replace with a new module. No electrical adjustment or alignment is required.

The SL85 pulse wheel assembly is imprinted with magnetic poles that provide higher pulse counts than traditional gear tooth wheels. The higher resolution provides greater accuracy and more precise speed control in your applications. For flexible usage, wheel assemblies are available in a variety of mounting configurations.

Features and Benefits:

  • Thru-shaft and end-of-shaft versions are standard; double C face sandwich version is also available
  • 64, 128, 256, 512, 1024, or 2048 pulses per revolution (PPR) with optional index pulse
  • 5-15VDC operation, bi-directional quadrature signals with high power, differential line driver outputs


The NorthStar brand SLIM Tach® SL85 is a mill duty digital tachometer with high immunity to grease, oil, salt water, dirt, fibers, and dust is optimized for AC vector motor applications.

Standard Operating Characteristics
Code: Incremental
Pulses per Revolution: 60-2048
Phasing Sense: A leads B for Counter-Clockwise rotation (CCW) viewing encoder-mounted end
Quadrature Phasing: 90° ± 22°
Symmetry: 180° ± 54°
Index: 270° gated to falling B edge
Number of Output Modules: Single or Dual Redundant

Input Voltage Requirement: 5-15 Volts DC, 45 mA typical per sensor module plus line driver load
Output Signals: Line Driver, 150mA source/sink
Frequency Response: 0 - 120kHz Data & Index
Electrical Immunity: 2kV ESD, Reverse Polarity, Short Circuit
Connector: 10 pin industrial duty latching, sealed NEMA 4 &12, IP65

Shaft Speed: 5,000 RPM
Mounting Configuration: 8.5” 180C face mount for NEMA MG1 standards
Housing Material: Cast Aluminum
Acceleration Rate: 3600 rpm/sec max
Shaft Length Required: 2.5” min
Allowable Shaft End-Play: ± 0.050”
Allowable Shaft Runout: 0.003” TIR

Operating Temperature Range: Std.: -40°C to +90°C, Extended: -40°C to +120°C
Storage Temperature Range: -40°C to +120°C
Humidity: to 98% RH (non-condensing)
Shock (Sensor Module): 1 meter drop test, 30 G’s Min
Vibration: 18 G’s @ 5-2000 Hz spectrum

Available Specifications:

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