Digital optical tachometer

Types of Digital Optical Tachometer

A digtal optical tachometer is a device used to measure the rotational speed of an object. It has a sensor and a light source that detects the object’s surface markings. The digital optical tachometer calculates the speed based on the number of times the markings pass the sensor and displays the result on a digital screen. There are various types of digital optical tachometers, which include:

• Handheld Digital Optical Tachometer

  This type of digital optical tachometer is designed to be held in hand. It is portable, and its main function is to measure the speed of rotating parts or objects. Since they are handheld, the batteries have to be regularly charged or replaced. They also have LCD screens that allow for easy viewing of data.

• Laser Digital Optical Tachometer

  These digital optical tachometers use lasers to measure the speed of rotating objects or surfaces accurately. They are particularly useful for measuring the speed of distant or small objects that are hard to reach or see. Because of the advanced technology used in these tachometers, they are more expensive than the others.

• Contact Digital Optical Tachometer

  These types of digital optical tachometers require physical contact with the object or surface being measured. They have a small probe or wheel that has to touch the surface to get accurate measurements. This type of digital optical tachometer is suitable for applications that require high precision and accuracy.

• Non-Contact Digital Optical Tachometer

  This type of digital optical tachometer does not require physical contact with the object or surface being measured. They use technologies like lasers or infrared to measure the speed. This type of digital optical tachometer is suitable for applications where contact could interfere with the measurement or where the object is fragile.

• Miniature Digital Optical Tachometer

  This type of digital optical tachometer is compact and small-sized. They are designed for applications where space is limited or for tasks that require measuring the speed of small or miniature rotating parts. Despite their small size, they are designed to be highly efficient and accurate.

Specification and Maintenance of Digital Optical Tachometer

Specifications of digital optical tachometers vary depending on the type and model. Here are some common ones:

• Measurement Range: This is the minimum and maximum RPM values that the digital optical tachometer can measure. Usually, it ranges from a few hundred RPMs to several thousand RPMs. For instance, a tachometer with a measurement range of 0 to 10000 RPM can measure the speed of low-speed motors and high-speed engines.
• Accuracy: This is the degree to which the digital optical tachometer's measurements can be relied upon. Typically, the accuracy of a digital optical tachometer is expressed as a percentage of the full-scale range or the actual reading. For example, a tachometer with an accuracy of ±1% of the full-scale range can have an error of 100 RPMs in a reading of 10000 RPMs.
• Resolution: This is the smallest change in speed that the digital optical tachometer can detect and display. The resolution is determined by the number of digits on the display and the measurement unit. A higher resolution means a more accurate and precise measurement. For example, a tachometer with a resolution of 1 RPM can detect speed changes of 1 RPM, while a resolution of 0.1 RPM can detect speed changes of 0.1 RPM.
• Power Source: Digital optical tachometers are powered by batteries or external power sources. Battery-powered tachometers are portable and convenient to use. However, they require frequent battery replacements or recharging. External power source tachometers are suitable for long-term measurements but have limited portability.
• Display: Digital optical tachometers have LCD or LED displays that show the measured speed. LCD displays are more common because they consume less power and are easily readable in bright light. Backlit or large displays are easier to read in low light or from a distance.
• Data Logging: Some digital optical tachometers can record and store speed data for later analysis. This is helpful for monitoring speed changes over time or for diagnostic purposes. The storage capacity, sampling rate, and data transfer options (e.g., USB or Bluetooth) are important for data logging.
• Features: Additional features such as max/min hold, average calculation, and alarm functions may be included in digital optical tachometers. These features enhance the usability and functionality of the device, making it more suitable for specific applications and tasks.

Here are some general maintenance practices for digital optical tachometers:

• Follow the manufacturer's instructions and recommendations for maintenance and care.
• Regularly check and clean the optical components (like lenses and sensors) to avoid dust and debris from interfering with their performance.
• Ensure that the batteries are fully charged or replaced when necessary to avoid unexpected shutdowns or inaccurate readings due to low power.
• Periodically, test the tachometer using a known speed reference to ensure accurate measurements.
• Protect the tachometer from extreme environmental conditions, such as high temperatures, humidity, or vibrations, which can affect its operation.
• Handle the tachometer with care and avoid dropping or subjecting it to strong impacts, which can damage its components.
• Periodically, inspect the digital optical tachometer for signs of wear or damage and promptly address any issues.
• Store the tachometer in a clean, dry, and protected environment when not in use.

How to choose digital optical tachometer

Choosing the right digital optical tachometer is crucial for ensuring accurate and reliable RPM measurements. Here's a comprehensive guide to help select the right digital optical tachometer:

• Measuring Range: The digital optical tachometer needs to have a measuring range that covers the expected RPM range of the targeted applications. If the RPMs are too high or too low, the optical tachometer will provide inaccurate measurements or damage the device.
• Accuracy and Resolution: High precision and resolution are essential for applications where precise RPM measurements are crucial. For critical measurements, opt for a digital optical tachometer with high accuracy and resolution.
• Data Logging and Storage: If there's a need to analyze RPM trends over time, consider choosing a digital optical tachometer with data logging capabilities. Some advanced models store measurements, enabling users to transfer data to a computer for analysis.
• Display and User Interface: Select a digital optical tachometer with a clear and easy-to-read display. Consider the interface that is easy to navigate and understand. Some models come with backlit displays that enhance visibility in low-light environments.
• Measurement Modes: Some digital optical tachometers offer supplementary measurement modes, such as contact and non-contact modes. Contact modes entail using a probe that touches the rotating object, while non-contact modes use laser beams to measure RPM from a distance. Choose the mode that suits the specific needs and applications.
• Portability and Size: Consider the size and weight of the digital optical tachometer. If portable and compact models are required for on-site measurements, choose smaller and lightweight optical tachometers.
• Battery Life: Evaluate the battery life of the digital optical tachometer, particularly if continuous measurements are required for long periods. Look for models with power-saving features or consider those with rechargeable batteries.
• Additional Features: Some digital optical tachometers come with additional features, such as laser pointers for precise targeting, backlit displays for low-light environments, or built-in averaging functions. Consider any supplementary features that may enhance functionality and convenience.
• Price: Compare prices from different suppliers and manufacturers to find a digital optical tachometer that fits the budget. However, opt for high-quality and accurate optical tachometers, as they provide reliable measurements and durability in the long run.

By considering these factors, selecting the right digital optical tachometer tailored to specific needs and applications becomes easier. Whether it's for automotive diagnostics, industrial machinery monitoring, or any other RPM measurement requirement, the right optical tachometer will ensure precision and reliability.

How to DIY and Replace Digital Optical Tachometer

Here's a step-by-step guide for replacing a digital optical tachometer:

• Turn off the power

  To begin, turn off the power to the device or machinery where the tachometer is being replaced. This is important to avoid accidents and ensure the safety of the personnel involved in the operation.

• Disconnect the old tachometer

  After that, the connections of the old tachometer must be disconnected. These connections may include power supply wires and signal output wires connected to the device being measured.

• Remove the mounting hardware

  Subsequently, the mounting hardware, such as screws or brackets, must be removed to release the old tachometer from its mounting location. This may require the use of appropriate tools, such as screwdrivers or wrenches.

• Install the new tachometer

  At this point, the new tachometer must be positioned in its mounting location. Subsequently, the mounting hardware must be installed and tightened to ensure that the tachometer is securely held in place.

• Connect the new tachometer

  Now, the power supply and signal output wires must be connected to the new tachometer, following the manufacturer's instructions. It is important to ensure that the connections are performed with the correct polarity and in accordance with the specified electrical parameters.

• Check the alignment

  The alignment of the optical sensor with the reference mark must be verified to ensure accurate speed measurement. If necessary, adjustments must be made to obtain the correct alignment.

• Turn on the power

  Once all connections and alignments have been verified, the power supply to the device or machinery where the tachometer has been replaced must be turned on. This will allow the new tachometer to start operating.

• Perform a functional test

  A functional test must be performed to ensure that the new tachometer is operating correctly and displaying accurate speed measurements. It is recommended to check the readings at different speeds to verify the proper operation of the instrument.

Q and A

Q1: How do you use a digital optical tachometer?

A1: To use a digital optical tachometer, first, turn it on and follow any initial setup instructions provided in the manual. Then, point the device's beam at the rotating object, such as a motor shaft, and apply the reflective tape if necessary. Finally, observe the digital display to read the measured RPM (revolutions per minute).

Q2: How accurate is the digital optical tachometer?

A2: The digital optical tachometer is highly precise. Its accuracy level can be affected by factors such as the distance from the rotating object, the quality of the reflective surface, and environmental conditions.

Q3: What are the advantages of a digital optical tachometer?

A3: Digital optical tachometers have several advantages. For instance, they are non-contact, which means they do not touch the rotating object while measuring. This feature reduces the risk of damage to the measured object and ensures the operator's safety. Additionally, they are compact and portable, making them easy to carry and use in various situations. Finally, digital optical tachometers provide precise and stable measurements.

Q4: Can a digital optical tachometer measure slow speeds?

A4: Yes, digital optical tachometers can measure low speeds. However, measurements at low speeds might be less accurate and require a longer measurement time.

Q5: Why does the digital optical tachometer give an error message?

A5: Digital optical tachometers can generate error messages due to various reasons, such as insufficient battery power, a dirty lens, or an error in the setup process. In this case, users need to check the device according to the instructions in the manual.