How to Use Reflective Tape Correctly with UNI-T UT371 Tachometer Malaysia
The UNI-T UT371 Non-Contact Tachometer requires a reflective target to measure rotational speed.
Incorrect tape placement can cause unstable readings, doubled RPM, missing results or measurements that cannot be repeated. Preparing the target correctly is therefore an important part of RPM measurement.
Why Does the UT371 Need Reflective Tape?
The UT371 directs a laser toward the rotating component.
When the reflective marker passes through the laser, light is returned to the tachometer. The instrument counts each detected reflection and calculates the number of rotations per minute.
For correct measurement, the UT371 should detect one reflection during each complete rotation.
Stop the Machine Before Applying Tape
Never attach reflective tape to moving machinery.
Before preparing the target:
Switch off the equipment.
Isolate the power supply.
Disable automatic starting.
Wait for every rotating component to stop.
Follow the site’s lockout procedure.
Confirm that the surface is safe to access.
Fans, pumps and other equipment may start automatically through controllers, timers or building management systems.
Select the Correct Measurement Point
Choose a target location that:
Rotates together with the component being measured
Is visible from a safe measuring position
Has enough space for the reflective marker
Is not covered by oil or water
Does not move sideways during rotation
Can be measured within approximately 50 to 200 mm
Suitable locations may include a shaft, pulley face, fan hub or coupling surface.
Do not remove permanent machinery guards unless authorised by the site’s safety procedure.
Clean the Target Surface
Reflective tape may detach or produce poor results when placed on a dirty surface.
Remove:
Oil
Grease
Dust
Moisture
Loose paint
Rust particles
Other adhesive residue
The surface should be dry before the tape is applied.
Use Only One Reflective Marker
For normal RPM measurement, attach one reflective marker per rotating component.
If two reflective markers are detected during each rotation, the displayed result may be approximately twice the actual RPM.
For example:
Actual shaft speed: 1,000 RPM
Two markers detected per rotation
Possible displayed result: Approximately 2,000 RPM
If the reading appears to be multiplied, inspect the rotating surface for additional reflective areas.
Reflective Tape Size and Placement
The marker must be large enough for the laser to detect consistently but should not unnecessarily cover a large part of the rotating surface.
Apply it:
Flat against the surface
Without wrinkles
Away from loose edges
Where it remains visible during rotation
In a position that does not affect machinery balance
Clear of areas where it may contact another component
For high-speed or sensitive rotating equipment, follow the equipment manufacturer’s requirements before attaching anything to the component.
Reduce Unwanted Reflections
Polished metal, labels, bolts and bright paint may reflect the laser and create additional signals.
To reduce unwanted detection:
Select a darker surrounding area where possible
Cover unnecessary reflective areas if safe and permitted
Change the measuring angle slightly
Keep the laser focused on the intended marker
Avoid aiming across multiple rotating surfaces
The reflective marker should create a clear contrast with its surrounding surface.
Maintain the Correct Measuring Distance
The UT371 target distance is approximately 50 to 200 mm.
During measurement:
Keep the tachometer steady
Aim directly at the marker
Avoid continuously changing the distance
Confirm that the marker passes through the laser point
Use a safe position away from belts, shafts and fan blades
A narrow target may require more careful alignment.
Common Problems Caused by Incorrect Tape Use
SymptomPossible Tape-Related CauseNo RPM readingTape is dirty, missing or not visibleReading appears doubledTwo reflective markers are detectedReading continuously jumpsMarker is too small, loose or partially visibleReading appears occasionallyLaser does not consistently reach the tapeReading is unexpectedly highPolished surfaces create extra reflectionsReading changes with instrument positionTarget alignment is inconsistent
Correct the target and repeat the measurement before assuming that the tachometer is faulty.
Replace Damaged Reflective Tape
Replace the marker if it becomes:
Dirty
Loose
Torn
Folded
Covered with oil
Difficult to detect
Partially detached
Stop and isolate the machine before replacing the tape.
Remove Tape After Measurement When Necessary
Reflective tape may be left as a permanent measurement point only when this is acceptable for the machinery and workplace procedure.
Remove it when:
It could detach during operation
It affects equipment balance
It may enter the production process
The surface must remain clean
The equipment manufacturer does not allow attachments
The machine operates under demanding environmental conditions
Always remove the tape while the machinery is stopped and isolated.
When the UT371 Still Cannot Measure
If a clean and correctly positioned marker does not produce a stable result, check:
Battery condition
Measuring distance
Strong surrounding light
Laser operation
Target visibility
Instrument stability
Expected RPM range
If the problem continues on different rotating targets, the instrument may require checking.
WhatsApp MTM Precision a clear photo of the UT371, its model label, the reflective target and a short video showing the measurement problem for an initial assessment.
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
30 Sep 2026
