Gurley Precision Instruments - Optical Encoders for Rotary and Linear Motion

We offer Optical Encoders for both rotary and linear motion, in conventional incremental and absolute configurations and in GPI’s unique Virtual Absolute™ technology. They are used to measure or control position and/or speed in medical instrumentation, electronic manufacturing equipment, robotics, factory automation, graphic arts and printing equipment, machine tools, radar p... (read more)

Gurley Precision Instruments - GPI Custom Encoders

Gurley has been a major designer and manufacturer of precise measuring instruments since 1845, and a leading supplier of optical encoders since the mid-1950s. We have a full catalog of standard products; most of them are on our web site. Please call if you don't see what you're looking for.

Although we have many catalog items, our real strength has always been our willingness and... (read more)

Gurley Precision Instruments - Gurley Pygmy Meters

The compact design of pygmy meters - the bucket wheel is just 3/4 inch by 2 inches in diameter - allows measurement of shallower and lower velocity flows. The pygmy meter provides reliable measurements of flows down to 0.05 feet per second at depths as shallow as 3 inches. Except for the absence of a five revolution click, these models operate identically to the larger Price type meters... (read more)

Gurley Precision Instruments - GPI's Line of Small, High Resolution Encoders

Only 0.75" dia x 0.9" long, the R119 is available with a 3-mm diameter shaft, or as a blind hollow-shaft encoder with flexible tether mount. (read more)

Gurley Precision Instruments - Spherical and Aspherical Optical Lenses

Gurley Precision Instruments manufactures a variety of optical lenses designed with performance in mind. In addition to our standard line of lenses, we also make custom parts for your demanding requirements. (read more)

Gurley Precision Instruments - Model 7700 Incremental & Virtual Absolute Encoder

The model 7700 Incremental and encoder is a compact, non-contact modular encoder with superior performance. Available in many resolutions and configurations, it is easy to install and its optional commutation tracks eliminate hall effect sensors for brushless motors.

Features common to both models include:

  • LED illumination for long life (>100,000 hours)<.../li>
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Gurley Precision Instruments - Gurley Absolute Linear Encoders

The Models LA18, LA20, LA25 and LA35 are optical absolute linear encoders designed for long life in medium to high-performance applications. The compact LA18 offers measuring lengths up to 1.2 m (48”); the almost-as-compact LA20 measures up to 1.5 m (60”); and the more robust LA25 and LA35 have a maximum measuring length of 2.0 m (80

... (read more)
Gurley Precision Instruments - WHAT IS OPTOGRAPHICS?

Optographics is the production of precision masters and the replication of these patterns in metallic depositions or photographic emulsions on various substrates. At Gurley Precision Instruments, we have taken Optographics from its infancy to the continuously expanding state of the art that we have today. Some of our more standardized Optographic products include:

Reticles,... (read more)

Gurley Precision Instruments - Neutral Density Filters

Gurley Neutral Density Filters allow the attenuation of light at multiple levels. (read more)

Gurley Precision Instruments - Model 4320DN Digital Timing Attachment

The Model 4320 Programmable Digital Timer is designed specifically for all Gurley Densometers and High Pressure models. (read more)

Gurley Precision Instruments - Model 4110N GENUINE GURLEYTM Densometer

Densometers are the accepted standard for measuring the porosity, air-permeability or air-resistance of sheet-like materials such as papers, wovens, plastics and membranes. (read more)

Gurley Precision Instruments - Gurley Model 4340 Automatic Densometer

Combination of low, standard and high pressure Gurley Densometers and smoothness testers

Our flagship instrument. The Model 4340 combines the abilities of our textile, standard and high pressure Densometers, S-P-S Testers as well as our programmable digital timers and provides a reading in seconds, thus reducing the time required to test a material. (read more)


Troy, NY – Gurley Precision Instruments' high-performance A08/R108 series rotary encoder offers both incremental (to 4,096 counts) and absolute (up to 12-bits) position information in an 8mm diameter package. Available in both a shaft and blind hollow-shaft configuration, the A08 and R108 offers design engineers several unique mounting and interface options. (read more)

Gurley Precision Instruments - True Absolute Rotary Encoder

GPI improves the resolution of the A19 Low-Cost, True Absolute Rotary Encoder to 15 bits! (read more)

Gurley Precision Instruments -  M122 Magnetic Rotary Encoder

Gurley Precision Instruments introduces a new magnetic encoder, the M122, which offers high performance in a small package (22-mm). The M122 includes a microchip equipped with a matching rotating magnet that provides four output options: binary parallel, synchro-serial (SSI), incremental (quadrature) and analog. (read more)

Gurley Precision Instruments - Model 7700 Virtual Absolute Rotary Kit Encoder

Gurley introduces its new compact, modular encoder designed for superior performance. Based on Gurley's patented Virtual Absolute technology, the model 7700 provides absolute positioning and high performance at a low price. (read more)

Gurley Precision Instruments - Model A58 Low-Cost Absolute Rotary Encoder

The A58 is the highest resolution compact encoder available for applications requiring precise measurements of distances and angles in a relatively small package. The low cost and high accuracy of this encoder make it an ideal solution for practically all applications which require absolute positioning. Mechanical features include a 58-mm diameter aluminum housing, a 3mm to 0.25" diameter stainles... (read more)

Gurley Precision Instruments - GPI Model R112 - Smallest High Resolution Encoder.

GPI Models R112S and R112B optical rotary incremental encoders are designed for light industrial applications that require high resolution in a very small package. Available in either shafted or blind-hollow shaft versions, these encoders are only 12mm dia x 25mm long with resolutions up to 8,000 cy... (read more)

Gurley Precision Instruments - Low-Cost Model A37: Mini Rotary Absolute Encoder

The model A37 mini encoder is a 12-bit single-turn absolute rotary encoder with opto-electronic technology. These encoders are used in a wide variety of position-sensing applications for the measuring of angles and distances in relatively small envelopes. Mechanical features include a 37-mm diameter aluminum housing, a 3-4 mm (0.125-0.25") diameter stainless steel shaft... (read more)

Gurley Precision Instruments - Virtual Absolute Technology

Gurley Precision Instruments has developed a unique encoding method that combines the simplicity of an incremental encoder with the reliability of an absolute encoder. (read more)

Gurley Precision Instruments - Models R258 and R260 Rotary Incremental Encoders

Rotary incremental optical encoders: Model R258 and R260 offer rugged use, high performance in both single and dual-shaft designs. (read more)


The model VL18 combines the opto-mechanical simplicity and ruggedness of incremental scale construction with the remarkable advantages of pseudorandom encoding. (read more)

Gurley Precision Instruments - AquaCalc 5000

Upgrade headphone and optical style outfits to compute total flow. (read more)

Gurley Precision Instruments - Model 1100 Digital Indicator

An economical choice for manual stream gauging and calculations.

The Gurley Model 1100 Digital Indicator contains CMOS circuitry to convert opto-electronical pulses from the meter to direct display of flow velocity. (read more)

Gurley Precision Instruments - Novel Virtual AbsoluteTM Decoder

Gurley Patents Virtual AbsoluteTM Decoder (read more)