Contact vs Non Contact Tachometer - Which Is Better Malaysia

Contact vs Non Contact Tachometer - Which Is Better Malaysia

Choosing between a contact tachometer and a non-contact tachometer is an important decision for factory maintenance teams, mechanical engineers and industrial equipment technicians in Malaysia.

Both instruments are designed to measure rotational speed, usually expressed in RPM (Revolutions Per Minute). However, they use different measurement methods and are suitable for different industrial applications.

A contact tachometer measures rotational speed by placing a suitable measuring attachment against a rotating surface or shaft.

A non-contact tachometer, such as the Benetech GM8905 Digital Laser Tachometer, measures RPM using an optical detection method without physically touching the rotating component.

The best choice depends on the measurement location, machinery accessibility, safety requirements, operating speed and whether the user needs rotational speed or linear surface speed.

This guide compares both tachometer types to help Malaysian industrial buyers select the appropriate instrument.

1. What Is a Contact Tachometer?

A contact tachometer is a measuring instrument that determines rotational speed through physical contact with a moving component.

Depending on the instrument design, it may use a rubber cone, contact tip or measuring wheel.

When the attachment touches a rotating shaft, the instrument detects its rotational movement and calculates RPM.

Some contact tachometers also support linear surface speed measurement when fitted with an appropriate measuring wheel.

Common Contact Tachometer Applications

Motor shaft speed measurement

Roller speed inspection

Conveyor surface speed measurement

Mechanical workshop testing

Rotating machinery inspection

Production equipment maintenance

Main Advantage: A contact tachometer can measure suitable rotating components without requiring reflective tape.

Main Limitation: The measuring attachment must physically contact the moving component, which may be unsuitable or unsafe for certain machinery.

2. What Is a Non Contact Tachometer?

A non-contact tachometer measures rotational speed without placing a measuring attachment against the rotating component.

Optical tachometers use reflected light to detect repeated rotations.

The Benetech GM8905 Digital Laser Tachometer is an example of a handheld non-contact RPM measuring instrument.

A reflective marker is normally attached to the selected rotating component while the machinery is safely stopped and isolated.

During operation, the instrument detects the marker as it passes through the optical measuring area.

The tachometer calculates RPM from the detected signal frequency.

Common Non Contact Tachometer Applications

Electric motor RPM verification

Industrial fan shaft measurement

Pump shaft inspection

Conveyor pulley RPM measurement

Machinery commissioning

Preventive maintenance

Main Advantage: The instrument measures RPM without requiring direct mechanical contact with the rotating component.

Main Limitation: A suitable optical target and clear line of sight are required.

3. Contact vs Non Contact Tachometer Comparison

The following table summarizes the main differences.

FeatureContact TachometerNon Contact TachometerMeasurement MethodPhysical contactOptical detectionRPM MeasurementYesYesReflective TapeNormally not requiredNormally requiredPhysical ContactRequiredNot requiredSurface Speed MeasurementAvailable on suitable modelsNot directly on basic optical modelsTarget AccessibilitySuitable contact point requiredClear optical target requiredMeasuring WheelMay be supportedNot requiredTypical ApplicationShafts, rollers and surface speedMotors, fans, pumps and rotating shaftsSafety ConsiderationContact with moving equipmentOptical access to moving equipmentMeasurement AccuracyDepends on instrument and contact conditionsDepends on instrument and optical conditions

Important: Neither measurement method is automatically more accurate or safer in every application.

The correct selection depends on the instrument specifications and actual measurement conditions.

4. Which Tachometer Is Better for Electric Motor RPM?

Electric motor RPM measurement is a common industrial maintenance requirement.

A technician may need to verify motor speed during:

Equipment commissioning

Motor replacement

Variable Frequency Drive adjustment

Routine maintenance

Mechanical troubleshooting

Contact Tachometer

A contact tachometer may be suitable when an approved shaft contact point is available and the equipment manufacturer permits the measurement method.

However, applying a contact attachment to a rotating shaft can introduce safety risks or affect measurement conditions.

Non Contact Tachometer

A non-contact tachometer such as the Benetech GM8905 is useful when a suitable reflective target can be observed from a safe position.

The instrument does not need to touch the rotating shaft.

Recommendation: For accessible optical targets where direct contact is undesirable, a non-contact tachometer is often a practical choice.

For a detailed measurement procedure, refer to our guide on How to Measure Electric Motor RPM Using Benetech GM8905 Tachometer Malaysia.

5. Which Tachometer Is Better for Conveyor Belt Speed?

Conveyor inspection may involve two different measurements:

Rotational Speed: The number of revolutions completed by a pulley or roller per minute.

Linear Speed: The distance travelled by the conveyor belt per unit of time.

These measurements are related but not identical.

Contact Tachometer for Conveyor Speed

A contact tachometer equipped with a suitable measuring wheel may measure conveyor surface speed directly.

The instrument must be designed and approved for the measurement method.

Non Contact Tachometer for Conveyor Speed

A non-contact tachometer measures the rotational speed of a pulley or roller.

To estimate conveyor belt linear speed, the operator needs additional information such as the effective pulley diameter.

For example:

Belt Speed (m/min) = π x Pulley Diameter (m) x Pulley RPM

If the effective pulley diameter is 0.2 metres and its rotational speed is 300 RPM:

Belt Speed = 3.1416 x 0.2 x 300

Estimated Belt Speed = 188.5 m/min

This calculation assumes the belt moves without significant slipping and uses the correct effective pulley diameter.

Recommendation: Choose a suitable contact measuring wheel instrument for approved direct linear speed measurements, or use a non-contact RPM meter with appropriate calculations when pulley RPM is the required measurement.

6. Which Tachometer Is Better for Industrial Fan Inspection?

Industrial fans are used in manufacturing facilities, ventilation systems and mechanical plant rooms.

Maintenance technicians may need to verify the rotational speed of the fan shaft or drive assembly.

Contact Measurement

A contact tachometer may be used where a suitable approved contact point is accessible.

However, fan guards, restricted access and moving components may make physical contact inappropriate.

Non Contact Measurement

The Benetech GM8905 can measure the RPM of a suitable rotating target using optical reflection.

The target must remain visible without removing or bypassing required guards during operation.

Recommendation: A non-contact tachometer may be preferable where a safe optical measuring point is available.

Note: Fan RPM is not the same as air velocity or airflow volume. Instruments such as the Benetech GM8902+ anemometer are used for airflow-related measurements.

7. Which Tachometer Is Better for Pump Maintenance?

Industrial water pumps are used in factories, water treatment facilities, cooling systems and building services.

Pump inspection may include checking motor speed, pump shaft speed and operating conditions.

A contact tachometer may be suitable for an approved accessible shaft contact point.

A non-contact tachometer may be suitable where a reflective target can be installed and observed safely.

The Benetech GM8905 can support pump and motor RPM verification when these conditions are met.

Important: Pump RPM measurement does not directly measure water flow rate, discharge pressure or pump efficiency.

These parameters require additional inspection methods and instruments.

8. Contact vs Non Contact Tachometer Accuracy

A common question is:

Which tachometer provides more accurate RPM readings?

The answer depends on the instrument specifications and measurement conditions.

Contact Tachometer Accuracy Factors

Possible sources of measurement error include:

Contact wheel slipping

Incorrect contact attachment

Inconsistent contact pressure

Measuring wheel wear

Shaft alignment

Instrument calibration condition

Non Contact Tachometer Accuracy Factors

Possible sources of measurement error include:

Incorrect reflective tape placement

Multiple reflective targets

Poor optical alignment

Unwanted surface reflections

Measurement outside the specified distance

Instrument calibration condition

A properly used contact tachometer can provide accurate measurements.

A properly used non-contact tachometer can also provide accurate measurements.

The instrument's stated accuracy specification and the measurement procedure are more important than assuming one technology is always superior.

9. Safety Comparison for Industrial RPM Measurement

Safety is an essential consideration when measuring rotating machinery.

Contact Tachometer Safety

Contact measurement may expose the operator to hazards associated with moving shafts, couplings and rotating equipment.

Potential hazards include entanglement, loss of control of the measuring instrument and contact with moving machinery.

Contact measurement should only be performed using an approved method and suitable equipment.

Non Contact Tachometer Safety

Non-contact measurement eliminates the need to press a measuring attachment against the rotating target.

However, it does not eliminate all machinery hazards.

The operator must still ensure:

The reflective marker is installed while equipment is stopped and isolated.

Required machine guards remain installed during operation.

The target is visible from a safe position.

No part of the operator's body enters a hazardous area.

Laser safety instructions are followed.

Never remove or bypass machinery guards simply to obtain an RPM reading.

If a safe measurement point is unavailable, choose an alternative approved method.

10. Measurement Range and Operating Conditions

When comparing tachometers, buyers should examine the measurement range and operating conditions.

RPM Measurement Range

Confirm that the instrument can measure the expected minimum and maximum rotational speed.

Operating Distance

For non-contact tachometers, confirm that the optical measuring distance is suitable for the intended application.

Shaft Accessibility

For contact tachometers, determine whether the required contact point can be accessed safely.

Surface Condition

For optical instruments, ensure that a suitable reflective target can be prepared.

Environmental Conditions

Dust, moisture, temperature and ambient lighting may affect measurement suitability.

Instrument Documentation

Check the manufacturer's datasheet for accuracy, resolution, operating limitations and maintenance requirements.

The Benetech GM8905 specifications should be verified against the current manufacturer documentation before purchase.

11. Can One Tachometer Measure Both RPM and Surface Speed?

Some tachometers are designed with both contact and non-contact measuring functions.

These instruments may include interchangeable measuring attachments.

However, not every tachometer supports both measurement methods.

The Benetech GM8905 is primarily a non-contact optical RPM measuring instrument.

It should not be assumed to provide direct contact wheel measurement or linear surface speed measurement.

If a customer requires both RPM and surface speed measurement, an appropriate multifunction tachometer may be more suitable.

12. Choosing a Tachometer for Factory Preventive Maintenance

A maintenance department may inspect several types of rotating equipment.

The following guide can help with instrument selection.

Maintenance RequirementSuggested Measurement MethodElectric motor shaft RPMNon-contact, where optical access is safeIndustrial fan shaft RPMNon-contact, where a safe target is availableConveyor roller RPMContact or non-contact, depending on accessConveyor belt linear speedApproved surface speed measurement methodPump shaft RPMContact or non-contact, depending on equipmentHigh-speed rotating machineryManufacturer-approved measurement methodEnclosed rotating equipmentBuilt-in sensor or approved alternative method

Selection Tip: Choose the instrument based on the measurement task rather than purchasing solely according to maximum RPM range.

13. Benetech GM8905 for Malaysian Industrial Maintenance

The Benetech GM8905 Digital Laser Tachometer is relevant for maintenance teams that require portable non-contact RPM measurement.

Typical applications include:

Manufacturing Plants

Checking rotating machinery speed during equipment setup and maintenance.

Mechanical Workshops

Verifying rotational speed of suitable workshop equipment.

Industrial Maintenance Contractors

Carrying out RPM inspections across different customer facilities.

Building Maintenance

Checking approved motor, pump and fan shaft measuring points.

Engineering Training

Demonstrating non-contact rotational speed measurement principles.

For applications requiring direct linear surface speed measurement, customers should consider an appropriate contact or multifunction tachometer.

14. Frequently Asked Questions

What is the main difference between contact and non-contact tachometers?

A contact tachometer measures rotational speed through physical contact, while a non-contact tachometer uses optical detection.

Is a laser tachometer better than a contact tachometer?

A laser tachometer is often useful when physical contact is undesirable and a safe optical target is available. The best method depends on the application.

Can the Benetech GM8905 measure motor RPM?

Yes. The GM8905 measures RPM using a non-contact optical method.

Can a non-contact tachometer measure conveyor belt speed?

It measures rotational speed. Belt linear speed requires additional calculations or an appropriate direct measuring instrument.

Which tachometer is more accurate?

Accuracy depends on instrument specifications, calibration and measurement conditions rather than the measurement method alone.

Does the GM8905 require reflective tape?

Reflective tape is normally recommended for reliable optical RPM measurement.

Is a contact tachometer suitable for high-speed machinery?

Only when the equipment and measuring instrument manufacturers permit the method and it can be performed safely.

Where can I enquire about the Benetech GM8905 in Malaysia?

Contact MTM Precision Sdn Bhd for product information, quotations and availability enquiries.

15. Buy Benetech GM8905 Digital Laser Tachometer in Malaysia

Looking for a digital tachometer in Malaysia for factory maintenance, motor speed testing or industrial machinery inspection?

MTM Precision Sdn Bhd supplies industrial testing and measurement instruments for mechanical, electrical and maintenance applications.

Our team can assist customers in selecting suitable instruments for:

Motor RPM measurement

Non-contact rotational speed testing

Industrial fan and pump inspection

Conveyor maintenance

Factory preventive maintenance

Mechanical engineering applications

We welcome enquiries from Kuala Lumpur, Selangor, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kelantan, Terengganu, Kedah, Perlis, Sabah and Sarawak.

For product quotations, stock availability and instrument selection, please contact us.

Contact MTM Precision Sdn Bhd

MTM Precision Sdn Bhd

Showroom & Service Centre:

No. 29-1 & 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia.

Tel: 03-8080 7172

WhatsApp: +6016-660 7346

Email: mtmpre@yahoo.com

Website: www.mtmpre.com.my

Business Hours: Monday to Friday, 9:00 AM - 6:00 PM

Contact MTM Precision for Benetech GM8905 Digital Laser Tachometer quotations and tachometer selection advice in Malaysia.