How to Measure Electromagnetic Fields Around Electrical Equipment Malaysia

Electrical panels, motors, transformers, power cables and industrial machinery can produce electromagnetic fields during normal operation.

For maintenance teams, electrical technicians and facility engineers, measuring these fields can help with workplace investigation, comparison measurements and electromagnetic environment assessment.

The TENMARS TM-190T is particularly useful for this type of work because it combines 3-axis low-frequency magnetic field, AC electric field and RF electromagnetic field measurement in one portable instrument.

What Electrical Equipment Can Produce Electromagnetic Fields?

Electromagnetic fields may be present around many types of electrical equipment, including:

Distribution boards
Switchboards
Transformers
Electric motors
Pumps
Compressors
Generators
Power cables
Control panels
UPS systems
Industrial machinery

The measured field can vary according to equipment type, electrical load, distance and measurement position.

This is why an EMF survey should normally involve multiple readings rather than one measurement.

First Identify What You Need to Measure

Before switching on an EMF meter, identify the likely source.

This is important because EMF is not one single measurement category.

Around conventional electrical equipment, low-frequency magnetic and electric fields may be relevant.

Around wireless equipment, RF electromagnetic fields may instead be relevant.

The TENMARS TM-190T can investigate both categories, making it useful when several types of sources exist at the same site.

Step 1 – Establish a Reference Reading

Do not immediately place the meter against the equipment.

Start farther away from the suspected source and establish a reference reading.

For example:

Background area → 3 m → 2 m → 1 m → normal working position

The exact distances should be selected according to the equipment, site conditions and purpose of the survey.

The objective is to understand how the measured field changes as you approach the source.

Step 2 – Select the Correct Measurement Function

For electrical equipment, determine whether you are investigating:

Magnetic field

AC electric field

Do not automatically use the RF measurement function simply because the instrument is described as an EMF meter.

RF measurement is intended for higher-frequency electromagnetic sources such as wireless communication equipment.

Correct measurement starts with selecting the appropriate field type.

Step 3 – Measure at Normal Working Positions

A very high reading immediately next to a piece of equipment may not represent normal workplace conditions.

It is often useful to take measurements where personnel normally:

Stand
Operate controls
Perform maintenance
Walk past equipment
Work for extended periods

This provides more meaningful information about the electromagnetic environment at actual occupied positions.

Step 4 – Compare Different Distances

Distance can have a major effect on electromagnetic field readings.

For example, measurements could be recorded as:

Position	Distance	Reading
Reference Area	Away from equipment	Record value
Point A	2 m	Record value
Point B	1 m	Record value
Point C	Normal operator position	Record value
Point D	Near equipment	Record value

This creates a much more useful record than simply writing:

“EMF reading = X.”

Without distance and location information, future comparison becomes difficult.

Step 5 – Record Equipment Operating Conditions

Electrical equipment does not always operate under the same load.

A motor under heavy load may create a different measurement environment from the same motor when lightly loaded or switched off.

Record information such as:

Equipment ON/OFF status
Operating load
Measurement location
Distance
Measurement mode
Reading
Date and time

For trend comparison, try to repeat measurements under similar operating conditions.

Why 3-Axis Magnetic Field Measurement Is Useful

Magnetic fields have direction.

If a meter measures only one axis, instrument orientation can affect the result.

The TENMARS TM-190T provides 3-axis magnetic field measurement, allowing field components across three directions to be evaluated.

This is particularly convenient when investigating machinery or electrical installations where the field direction is not known beforehand.

Measuring Around Electrical Panels

Electrical panels are a common EMF investigation point.

A simple survey may include readings:

Away from the panel
In front of the panel
At the operator position
Beside the panel
Near incoming or outgoing cables

If one area produces a noticeably different reading, additional measurements can be taken to understand how the field changes with position.

Measuring Around Electric Motors

Electric motors are widely used in Malaysian factories.

They may be found in:

Pumps
Fans
Compressors
Conveyors
HVAC systems
Production machinery

When investigating around a motor, take readings at consistent positions and distances.

If measurements will be repeated for comparison later, mark or document the measurement points.

Consistency makes trend data much more useful.

Measuring Around Transformers

Transformers can also be relevant sources of low-frequency electromagnetic fields.

Measurements can be taken at different distances around the installation, including normal occupied or maintenance positions.

Do not assume that the highest reading at the equipment surface represents exposure at normal working locations.

Distance should always be documented.

Measuring Around Power Cables

Current-carrying cables can produce magnetic fields.

The measured value can depend on:

Current
Cable arrangement
Distance
Measurement position
Nearby conductors

When investigating cable routes, technicians can take readings at several points and compare them rather than relying on a single measurement.

What If Wireless Equipment Is Nearby?

Modern factories and commercial buildings often contain both electrical and wireless equipment.

For example, the same room may contain:

Electrical panels
Machinery
WiFi access points
Wireless sensors
Communication equipment

This is where the TM-190T's multi-field capability becomes useful.

For RF electromagnetic fields, the TM-190T provides measurement coverage from 50 MHz to 10 GHz.

The technician can therefore investigate different electromagnetic field categories using one instrument.

EMF Testing in Factory Maintenance

EMF measurement can be incorporated into broader facility or maintenance investigations.

Potential locations include:

Production areas
Electrical rooms
Plant rooms
Generator rooms
Pump rooms
HVAC installations
Server rooms
Control rooms

The objective should be clearly defined before measurements begin.

A general investigation, troubleshooting exercise and formal compliance assessment may require different procedures.

Does a High Reading Automatically Mean the Equipment Is Unsafe?

No.

A measurement value should not automatically be described as “safe” or “dangerous” without the appropriate context.

Interpretation may depend on:

Field type
Frequency
Measurement units
Exposure duration
Measurement method
Applicable occupational or regulatory guidelines

If formal compliance assessment is required, the relevant standard and measurement procedure should be identified before testing.

Common EMF Measurement Mistakes

Avoid these common problems:

Measuring without recording distance

The number becomes difficult to interpret or reproduce.

Using the wrong measurement mode

Low-frequency electrical fields and RF fields are different measurement categories.

Taking only one reading

Conditions may vary significantly around equipment.

Comparing measurements taken under different loads

Equipment operating condition can affect results.

Calling every elevated reading dangerous

Measurement results need appropriate technical context and applicable limits before conclusions are made.

Why Use TENMARS TM-190T?

The TENMARS TM-190T is useful when technicians need a portable instrument capable of investigating several electromagnetic-field categories.

Its applications can include:

Electrical equipment investigation
Factory maintenance
Workplace EMF surveys
Electrical rooms
Server rooms
Data centres
Wireless and RF environments

Its combination of 3-axis low-frequency magnetic field, AC electric field and RF measurement up to 10 GHz provides flexibility for mixed industrial and commercial environments.

Looking for an EMF Meter for Electrical Equipment in Malaysia?

MTM Precision Sdn Bhd supplies TENMARS testing and measurement instruments in Malaysia.

If you need an EMF meter for a motor, transformer, electrical panel, factory machine, server room, data centre or wireless system, tell us the application before purchasing.

We can help determine which type of EMF measurement is relevant to your equipment.

Contact MTM Precision

MTM Precision Sdn Bhd
Showroom & Service Centre – Puchong, Selangor, Malaysia

WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my

Serving customers throughout Selangor, Kuala Lumpur, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kelantan, Terengganu, Kedah, Perlis, Sabah and Sarawak.

Contact MTM Precision for TENMARS TM-190T quotation, EMF meter selection and electrical testing enquiries in Malaysia.