The Lutron DT-2236 Digital Optical & Contact Tachometer

The Lutron DT-2236 Digital Optical & Contact Tachometer
4 July 2024

Determining issues for motors and other rotational forms of machinery can often be identified by monitoring their speed in operation. With proper maintenance, using a tachometer can determine variances in speed over time, leading to an intervention for maintenance ahead of a potential mechanical failure.

Automated Conveyor System speed needs to be monitored regularly
Automated conveyor system motors often require speed monitoring and calibration

Tachometers can often be found as a part of maintenance engineers and technicians' tool kits for almost all motors and mechanical systems, such as simple conveyor belt systems, mechanical metal press machines and complex HVAC pumps & fan systems. 

In this article, we cover the specifics and applications of the Lutron DT-2236 Digital Optical & Contact Tachometer for applications requiring speed monitoring in machinery and motors.

Lutron DT-2236 Digital Tachometer Key Takeaways

  • Tachometers are used to measure the speed of rotational machinery.
  • The Lutron DT-2236 features both Optical & Contact Tachometers.
  • Optical Tachometers produce light, measuring reflections from a reference point on the rotational machine, producing an RPM measurement.
  • Contact Tachometers contact the rotating device, generating pulses converted to RPM measurement.


LUTRON DT-2236 Photo Contact Tachometer
The Lutron DT-2236 Digital Optical & Contact Tachometer. Learn more about the Lutron DT-2236 here


What is a Digital Tachometer?

A digital tachometer is a lightweight handheld device applied to rotating machinery and motors to determine speed. A digital tachometer, when applied to an application, will rotate, and generate an electric pulse within the device, whilst calculating an average voltage in the device will correlate to the revolutions per minute of the machine being measured and display a digital readout on the device.

The Lutron DT-2236 Digital Tachometer provides users with the convenience of two-in-one measurement types, both an optical and a contact tachometer.


What is an Optical Tachometer?

Optical tachometers produce a laser or beam of light, which pairs with a reflective mark placed by the user on the rotating device. To take measurements with the optical tachometer, the user simply places the reflective mark/adhesive onto the surface of the intended motor or machinery and places the optical tachometer in a stable/fixed position to count the revolutions of the reference mark, whilst the machine is in operation.

The tachometer will count how many times it has been reflected onto itself and interpret it as a revolution/speed for the user to review.

The Lutron DT-2236 is useful for monitoring the rpm of conveyor belts and other motor driven belt systems
Lutron DT-2236 Optical Tachometer is useful for measuring the RPM of motor belt systems


What is a Contact Tachometer?

Contact Tachometers conversely will need to be physically touching the rotating part of the machine, such as the shaft of an electric motor. To measure with a contact tachometer, the user simply takes the moving part of the tachometer and is placed in direct contact with the shaft or disc attached to the motor. With each revolution, the contact tachometer produces a small electric pulse which the device interprets as the RPM of the motor or rotational device being measured.


Lutron DT-2236 Contact Tachometer makes contact with the rotating shaft of the motor
Lutron DT-2236 Contact Tachometer makes contact with the rotating shaft of the motor


Specifics of the Lutron DT-2236

As the Lutron DT-2236 offers users both optical & contact tachometer options, there is only one real variance, the optical tachometer options offer users a measurement & range of 5 to 99,999 RPM, whereas the contact tachometer option offers users from 0.5 to 19,999 RPM. 

The device provides resolutions for:

Photo Tachometer/Contact Tachometer

  • RPM: 0.1 (< 1,000 RPM) / 1 RPM (1,000 RPM)
  • Meters/Min: 0.01m/min (<1,000 ft/mn) / 1ft/min. (100m/min)
  • Ft/Min: 0.1 ft/min (<100m/min) / 1ft/min (1,000 ft/mn).

To learn more about the specifics of the Lutron DT-2236 here.


The DT-2236 is a robust, yet lightweight (280g) handheld tachometer that should be an essential tool of every maintenance engineer's toolkit. Using this device regularly can ensure your system remains operational, by allowing for early intervention ahead of mechanical failures on essentially all motor and rotating mechanical devices. 

If you’d like to learn more about the Lutron DT-2236 and how it may be useful to your next application, the ADM Team is here to help. Send an enquiry here or call us on 1300 236 467.