Tachometers – find manufacturers and suppliers

Tachometers or revolution counters are used to measure the rotational speed of a rotating object, typically in revolutions per minute (rpm).

They are used in many areas, including mechanical engineering, the automotive industry, production, aerospace and research and development.

Below you will find how different tachometers work and how they are used, their output and display forms and their areas of application:

How different tachometers work and how they are used:

Tachometers measure the speed of rotating objects using various measuring methods. Here are the most common types of speed measuring devices and how they work:

1. Contact tachometers:
   These devices have a roller or attachment that comes into direct contact with the rotating shaft.
   The mechanical rotary movement is then converted into electrical signals that enable the speed to be displayed.
   Application: Suitable for machines where direct contact with the rotating shaft is possible, such as motors or drive shafts.
2. Optical (laser) tachometers:
   These devices use lasers or light beams to detect the movement of the rotating surface.
   Reflection marks on the rotating object reflect the light and the speed is calculated based on the number of reflections per unit of time.
   Application: Ideal for non-contact measurements on machines that are difficult to access or sensitive, such as turbines, large motors or conveyor systems.
3. Magnetic speed tachometers:
   They use magnetic fields to detect metal parts on the rotating shaft.
   With each revolution, the metal part generates a change in the magnetic field, which is used to calculate the speed.
   Use: Commonly used in harsh industrial environments where dust, dirt or vibrations are present as they are robust and non-contact.
4. Inductive tachometers:
   Work on the principle of inductive measurement.
   When a metal tooth or other part of the rotating shaft passes a sensor, an induction voltage is generated which is used to measure the speed.
   Use: Very reliable in metal applications, such as in motors and turbines, and well suited for precise measurements in industrial environments.
5. Hall effect sensors:
   These sensors use the Hall effect to detect the movement of magnetic materials on a rotating shaft.
   Application: Suitable for non-contact speed measurement in industrial applications or machines subject to heavy mechanical loads.

Output and display forms for tachometers:

• Modern tachometers offer digital displays that show the measured speed in real time. These displays are often equipped with additional functions such as storing maximum values or alarms.
• Some older or simpler devices offer analog measured values via scales or pointers.
• Many tachometers have outputs (e.g. 4-20 mA, 0-10 V, or digital signals such as RS232 or CAN) that can be connected to control systems or data loggers. Signal transmission to automation systems is important in industrial monitoring in order to analyze the data in real time and adapt processes.

Areas of application for tachometers:

1. Industrial machine monitoring:
Tachometers monitor the speed of motors, pumps, turbines and conveyor belts. This allows deviations in speed to be detected and maintenance measures to be initiated in good time.

2. Automotive industry:
Here, tachometers are used to measure engine speed or wheel speed in order to monitor and analyze vehicle performance.

3. Wind turbines:
The speed of the rotor blades is monitored to ensure the efficiency of energy conversion and avoid overloads.

4. Aerospace:
Engine or rotor speed is monitored to optimize and ensure aircraft performance.

5. Research and development:
Tachometers are used in laboratories to measure and analyze the rotational speeds of test objects.

Tachometers are essential instruments for monitoring and controlling rotating machines and systems. They are used in a wide range of industrial and technical applications, from motor control to research and development.

Below you will find an overview of the most important criteria that you should pay attention to when purchasing tachometers:

When buying a tachometer, there are a number of important criteria that depend on the application and environmental conditions.

• The measuring range of the tachometer should meet the specific requirements of the application. Depending on the area of application, low speeds (e.g. in conveyor belts) or very high speeds (e.g. in turbines) may need to be measured.
• It may make sense to choose a device that covers a slightly larger measuring range to take possible future requirements into account.
• The measuring accuracy indicates how accurately the device measures the actual rotation speed. High accuracy is particularly important in applications such as research and development or when monitoring sensitive machine processes.
• The resolution indicates how finely the tachometer can display the measured values. A higher resolution is advantageous for applications in which the smallest speed changes must be recorded, such as in the fine control of motors.
• With contact speed measurement, the sensor comes into physical contact with the rotating shaft. These devices are inexpensive but prone to wear and are not suitable for all applications. Ideal for stable environments where direct measurements are possible, e.g. in manufacturing or testing facilities.
• Non-contact measuring devices (optical or inductive) measure speed without physical contact with the rotating shaft, often using laser or magnetic field technologies. They are more durable and suitable for more sensitive or difficult to access measuring points. Ideal for high-speed applications, inaccessible machines or measurements where mechanical stress must be avoided.
• Digital displays enable simple and precise reading of the measured speed. Many modern devices offer additional functions such as saving maximum or minimum values and alarms when limit values are exceeded.
• Simple tachometers often use analog scale displays, but these are less precise to read than digital displays.
• Some tachometers offer connection options for external displays or computers to monitor and save measurement data in real time.
• Devices with internal memory allow measurement data to be recorded and analyzed later. This is particularly useful in long-term monitoring projects.
• Devices with interfaces for exporting measurement data (e.g. via USB or wireless interfaces) enable easy integration into data acquisition systems or transfer to computers for further analysis.
• Depending on the control system, suitable interfaces such as 4-20 mA, 0-10 V or digital outputs (e.g. RS232, RS485, CANopen) should be selected in order to feed the measurement results into higher-level systems.
• For industrial applications that require real-time monitoring and control, integration into networks (e.g. Ethernet, Profibus) is crucial to ensure seamless communication with automation systems.
• In industrial environments, it is important that speed measuring devices are protected against dust, water and other environmental influences. A high protection class IP-IP65 or higher is therefore an advantage.
• For applications in extreme environments, such as near motors or machines that generate high temperatures, care should be taken to ensure that the device is designed for the temperature range.
• Some devices offer flexible mounting options so that they can be easily installed in different locations or positions.
• Especially for large machines or in areas where the measurement takes place far away from the monitoring point, the length and quality of the connection cables is crucial for precise signal transmission.
• If a portable or mobile device is chosen, attention should be paid to the battery life, especially if the device is used for long periods of time or in hard-to-reach places.
• Some devices offer the option of using rechargeable batteries, which helps with ongoing running costs.
• Devices should be calibratable to ensure accurate measurements over their lifetime. Some meters offer automatic calibration functions.
• Contact devices often require more maintenance than non-contact devices due to mechanical wear and tear. Attention should be paid to how often maintenance is required and how easy it is to carry out.
• In certain industries, such as the automotive, aerospace or medical industries, speed measuring devices must meet certain standards and certifications, such as ISO or DIN. It is important to ensure that the selected device meets the respective requirements.
• For applications in potentially explosive environments (e.g. chemical industry, oil and gas industry), tachometers should be ATEX-certified to ensure safety.
• It is important to select the tachometer according to the specific requirements and not to invest unnecessarily in functions that are not needed in the respective application.
• Cheaper devices may appear attractive at first glance, but long-term maintenance costs and the lifetime of the devices can quickly cancel out the initial savings. High-quality and robust devices often have a longer service life and offer a better overall return on investment.

When purchasing a tachometer, it is important to consider the specific application and environmental conditions, and careful selection of the right device can ensure accurate measurements and long-term, reliable use.

Tachometers can be purchased from various suppliers. You will find comprehensive information on manufacturers and suppliers of Tachometers around the world on Exportpages.