Digital tachometers are smart devices that enable the user to measure the speed of any motor’s shaft or any other rotating object such as the chuck of a lathe machine. The device is designed to measure the rotational speed of objects without any physical contact.

Traditional analog tachometers worked by physically contacting on revolving parts and they were comparatively harder to operate. Changing their tip according to the shaft type and holding tip onto running shaft wasn’t as easy as just directing laser light on the shaft from a distance. Laser tachometers are much safer with their no-contact feature as the user doesn’t need to make physical contact of the device with any fast-moving object like a lathe machine’s chuck. Furthermore, recording values is easier with digital display.

This product is used by lot of academic institutions and businesses in nz.

Main Features of Digital Tachometer:

• Digital display
• Reliable results
• Easy to operate
• Smooth and easy to carry
• Light weight
• Strong case
• Durable device

 Digital Tachometer Specifications:

• Min/max/last reading recording feature
• Test range 2.5-99999 RPM
• Sampling time: 0.8 seconds over 60 RPM
• Accuracy: ± (0.05% + 1 digit)
• Operational environment: 0-50 degree Celsius, Humidity <80%RH 
• Dimensions: 160x76x40mm
• Resolution: 0.1 RPM (2.5 to 999.9 RPM), 1 RPM (over 1,000 RPM)
• Power Source: 9V battery
  
• Weight: 280g
  
• Battery not included
  

How Does a Laser Tachometer Work?

The laser tachometers emit laser light and when the light strikes on any dark surfaces, no or very less light is reflected back to the tachometer. But, when the light strikes on a bright or shiny surface, a comparatively higher level of light reflects back. The photo sensor in tachometer detects the light signal over a specific time period and accordingly measures the speed of the motor. When a piece of reflective tape is pasted on the shaft of the motor, every time the laser strikes on the tape, the tachometer counts a revolution.

Apart from taking speed readings, digital tachometers also store min/max speed readings for better performance. The test button enables the user to calibrate or practice before taking any readings.

For more details on how to use Laser Tachometer, check this video

https://www.youtube.com/watch?v=QVSQLfnKytk

Applications of Tachometer:

The applications of tachometers are usually related to the measurement of a motor’s speed. But they can be used for measuring the rotational speed of any object.

• In order to calibrate the speed of a motor’s speed, it is essential to measure its speed. Tachometers are widely used for calibration in the industry for monitoring the speed of motors on conveyor belts and other parts of operations.

• The speed of the lathe machine is directly affective on its performance. While working on sensitive projects, the operators check its speed and set as needed.

• Motor windings can often burn due to excessive heating or overloading. In such cases, the motors are rewound, but once rewound the RPM of the motor may no longer be the same as before. In order to measure the new RPM, tachometers can be helpful.

• Tachometers are useful in all places where the speed of a motor has to be monitored. Similarly, the speed of a generator’s shaft can give an idea of how much energy will be generated, for such details, a tachometer can be helpful. In small scale hydro generators on canals and wind turbines, the rotational speed has to be analysed for determining the power and frequency parameters.

• Industrial machinery: Monitor the speed of motors, conveyors, pumps, and other machinery

• Manufacturing: Measure the speed of lathes, drill presses, and other metalworking equipment

• HVAC: Monitor the speed of fans and blowers

• Science and research: Measure the speed of laboratory equipment such as centrifuges and electric motors

• Agriculture: Measure the speed of tractor PTO and shafts on farming equipment

• Measure the speed of robotic arms, conveyors, and other automated systems

Projects Related to Motor Speed Control: 

555 timer-based DC motor speed control

https://www.electronicshub.org/speed-control-of-dc-motor-using-pulse-width-modulation/

DC motor speed control with Arduino and potentiometer

https://www.instructables.com/id/Arduino-DC-motor-speed-control-potentiometer/

Arduino based AC motor speed control

https://create.arduino.cc/projecthub/saulius-bandzevicius/arduino-based-universal-ac-motor-speed-controller-a4ceaf

FAQs:

1. What is the maximum range of this tachometer’s reading?

This device is capable of reading RPM up to 99999.

2. Is it useable for measuring the rotational speed of objects other than motors?

Yes, it can be used but the device may not perform well if proper conditions are not met.

3. Is it necessary to use reflective tape for measuring?

Yes, the reflective tape ensures that the laser light reflects back toward the photo sensor and the tachometer counts a revolution. However, in case of some motors, a part of the shaft is already shiny or a shiny sticker is already present for the same purpose. In that case, using a reflective tape is not necessary.