Tachometers play a crucial role in many fields, especially in industry and automotive, to ensure the performance, safety, and longevity of machinery.

Tachometer – Testo 470 (1 to 99999 rpm)

The importance of using a tachometer:

• Engine performance monitoring: Tachometers accurately measure the rotational speed (RPM – revolutions per minute) of motors, shafts, propellers, etc., providing crucial data for evaluating the current operating performance of machinery.
• Ensuring operational safety: Maintaining the rotational speed within the design limits is crucial to prevent machine damage, over-revving, and potential accidents.
• Preventive maintenance: By monitoring rotational speed over time, engineers can detect early signs of abnormalities or impending problems, allowing for timely maintenance or repairs, saving costs and downtime.
• Optimizing the production process: In manufacturing industries, precise speed control helps optimize processes, improve product quality, and minimize energy consumption.

 Tachometer Nidec DT-207LR LED Display with 6″ Circum Measuring Wheel

The main application of tachometers is their widespread use in many different industries:

• Automotive & Aerospace Industry: Measure engine speed, propeller speed, etc.
• Manufacturing & Mechanical Engineering: Monitor the speed of conveyor belts, rollers, motors, and turbines.
• Research & Development: Measuring rotational speed in experiments and tests.

The basic operating principle of a tachometer is to measure the frequency of rotational events within a specific time interval and convert the result into rotational speed (RPM – revolutions per minute). Different types of tachometers use different sensing methods to detect these events. 

Here are the operating principles of the two most common types of tachometers:

1. Non-contact tachometer

This type operates on optical or laser principles without requiring physical contact with the rotating object. 

• How it works: The user affixes a small piece of reflective tape to the surface of the object to be measured (e.g., an engine shaft). The measuring device then emits a laser beam or light towards this piece of tape.
• Detection and calculation: As the object rotates, the reflective strip reflects light back to the sensor of the measuring device with each rotation. The sensor counts the number of times it receives the reflected signal within a defined period (e.g., 1 second), after which the device's microprocessor calculates and displays the rotational speed in RPM. 

ONO SOKKI HT-4200 Non-Contact Tachometer 30 – 50,000 rpm

2. Contact Tachometer

This type requires direct physical contact with the rotating part. 

• How it works: A mechanical probe (usually a rubber wheel or pointed tip) is attached to the sensor and pressed against the shaft or rotating surface.
• Detection and calculation: As the object rotates, the sensor head rotates as well. This rotational movement is transmitted to an internal mechanism in the meter, generating electrical signals or pulses. Similar to non-contact types, the number of these pulses or signals is counted and converted into an RPM value on the display screen. 

ONO SOKKI HT-5500 electronic tachometerDual Contact / Non-Contact type)

Additionally, the rotational speed (RPM) of an object can be measured using Stroboscope

Stroboscopes work based on a visual phenomenon called stroboscopes. stroboscopic effect, taking advantage of the persistence of vision characteristic of the human eye.

Testo 477 – LED stroboscope (300,000 flashes per minute (FPM))

How to measure speed using a Stroboscope

To measure the rotational speed (RPM) of an object using a stroboscope, the user proceeds as follows:

• Adjust the frequency: Increase or decrease the flash frequency (measured in FPM – flashes per minute) until the object appears stationary and sharpest.
• Read the results: When the image of a stationary object is stable, the strobe frequency displayed on the stroboscope screen is the object's rotational speed (RPM).

NIDEC DT-3015N-JP battery-powered xenon Stroboscope

You can contact Semiki Instrumentation Co., Ltd directly for advice and to purchase a suitable tachometer.

Identify needs: What type of machinery (motor, conveyor, fan, etc.) do you need to measure speed for? Do you need a contact or non-contact type? What is the speed range you need to measure? Provide your requirements to Semiki's sales department. Semiki specializes in providing precision measuring equipment and will advise you on the model that best suits your technical needs.

Contact Semiki directly: You can find Semiki's contact information (via website or phone number) to request a quote and specific advice.

Website: You can find out more details and send a consultation request via Semiki.com.

Business email: [email protected]

Phone number (Hotline): +84 979 761 016.