EXTECH EMF450 Multi Field EMF Meter User Manual

: June 13, 2024
: EXTECH

Table of Contents

EXTECH EMF450 Multi Field EMF Meter
Product Information
Product Usage Instructions
Safety Information
Introduction
Features
Definitions
Descriptions
Operation
Battery Installation and Replacement
Specifications
References
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EXTECH EMF450 Multi Field EMF Meter

Product Information

The Multi-Field EMF Meter, Model EMF450, is a device used to measure radiated electromagnetic fields. It can detect voltage, current, electric (E) field, and magnetic (H) field. This includes electromagnetic fields from radio broadcasting, TV transmitters, and power lines. The meter measures electric field strength in volts per meter (V/m) and magnetic field strength in amperes per meter (A/m). It also provides power density measurements in watts per square meter (W/m2) or milliwatts per square centimeter (mW/cm2).

Product Usage Instructions

Power ON/OFF:
- Press the power button to turn on the meter. The main measurement screen will be displayed.
- If the meter does not power on, check that the batteries are installed correctly and are fresh.
- To turn off the meter, press and hold the Power button for 3 seconds.
Data hold (HOLD):
- Press the HOLD button to freeze the current readings on the display. The HOLD display icon will appear when this mode is active.
- To release the data, press the HOLD button again.
Electric Field Measurements:
- The EM450 measures the electric field (Electrical Power) in the atmosphere of the sensor’s surroundings.
- Hold the meter at the bottom and at arm’s length, as shown in Figure 3.
- Perform all tests according to the indicated direction of the electric field sensor.
Low Frequency EMF Readings (Magnetic field):
- Point the front section of the meter towards the desired electromagnetic field to take a measurement.
- The meter simultaneously displays the electromagnetic field readings of individual (XYZ) and the aggregated magnetic field readings.

Additional User Manual Translations available at www.extech.com

Safety Information

CAUTIONS

Before making a measurement, check if the low battery symbol is shown on the display when the meter is switched on. Replace the battery if the symbol is displayed.
In the case of prolonged storage, remove the battery from the meter to prevent damage.
Do not expose this device to direct sunlight or to extreme temperatures and humidity.
The accuracy and function of the meter may be adversely affected if the specified limits are exceeded or if the meter is handled improperly.
Clean the device with a soft, dry cloth. Moisture can damage the meter.
Electric field measurement precautions: Perform tests according to the indicated directions.

WARNINGS

Use caution when working in the vicinity of powerful radiation sources.
Persons with electronic implants (e.g. cardiac pacemakers) should avoid powerful radiation sources.
Observe all relevant safety regulations.
Carefully read the operating instructions for equipment generating or conducting electromagnetic energy that will be measured.
Do not operate near combustible gases or in damp environments.
Be aware that the field strength in the near vicinity of radiators increases proportionally to the inverse cube of the distance. This means that enormous field strengths can result in the immediate vicinity of small radiation sources (e.g. leaks in waveguides or inductive ovens).
Field strength measurement devices can underrate pulsed signals, particularly with radar signals, in which case significant measurement errors can result.
All field strength measuring devices have a limited specified frequency range. Fields with spectral components outside of this frequency range are generally incorrectly evaluated and tend to be underrated. Before using field strength measuring devices be certain that all field components to be measured lie in the specified frequency range of the measuring device.
For indoor use; Pollution level II
Operating altitude below 2000’ (6562’)

Introduction

This meter simultaneously measures and displays Magnetic Field, Electric Field, and RF Strength. The unit of measurement and the measurement types are expressed in units of electrical and magnetic field strength and power density. This meter is ideal for EMF measurements of power lines, electrical appliances, industrial devices, cell phones, base stations, and microwave leakage. This device is shipped fully tested and calibrated and, with proper use, will provide years of reliable service. Please visit our website (www.extech.com) to check for the latest version of this User Guide, Product Updates, Product Registration, and Customer Support

Features

Data hold (HOLD)
Overload display “OL”.
Brightness options: low-medium-high
Selectable Auto Power off (APO) Time: 1; 3; 5; 10; 15; 30 minutes
Key press Sounds / Alarm Sounds: On ; Off with programmable tone selections
Information screen shows software version
Languages: English, Traditional Chinese, Simplified Chinese, Japanese, Spanish
Magnetic units selection：Gauss (mG) or Tesla (μT)
Electric field strength: V/m
RF Strength Units selection: (μW/m² ~mW/m²) (μW/cm²) (m V/m ~V/m) (mA/m) (dBm).
Low-Frequency EMF Readings: Individual and aggregated XYZ axial readings :
High-frequency EMF Readings
RF Historical Records; up to 20 groups.
Low battery indication： HIGH LOW

Definitions

Electromagnetic Radiation
This meter is used to indicate radiated electromagnetic fields wherever there is a voltage, current, electric (E) or magnetic (H) field. Examples include the electromagnetic fields from radio broadcasting, TV transmitters and power lines.
Electric Field Strength
This is a field vector quantity that represents the force (F) on an infinitesimal unit positive test charge (q) at a point divided by that charge. Electric field strength is expressed in units of volts per meter (V/m). Use the units of electric field strength for measurements in nearfield power measurements.
Magnetic field strength (H)
This is a field vector that is equal to the magnetic flux density divided by the permeability of the medium. Magnetic field strength is expressed in units of amperes per meter (A/m). This measurement is for near-field power measurements.
Power density (S)
Power per unit area in the direction of propagation; usually expressed in units of watts per square meter (W/m2) or, for convenience, milli-watts per square centimeter (mW/cm2).
The characteristic of electromagnetic fields
Electromagnetic fields propagate as waves and travel at the speed of light (c). The wavelength is proportional to the frequency.

Near-field is assumed if the distance to the field source is less than three wavelengths. For far-fields, the distance is more than three wavelengths. In the near-field, the ratio of electric field strength (E) and magnetic field strength (H) is not constant, so measure each separately. In the far-field, however, it is enough to measure one field quantity, and compute the other accordingly

Descriptions

Front Panel Description

2.4” Color TFT display (240*320 resolution)
Select and Down button
Power and Menu button
Hold and Enter button
Battery compartment cover and measurement chart on back of meter

Display description

Data Hold
Auto power off (APO)
Audible alert
Battery status
Magnetic Field bargraph
Magnetic Field digital reading
XYZ axes values
Electric Field bargraph
Electrical Field digital reading
RF strength bargraph
RF strength histogram display
Select
Menu
Hold / Enter
RF electronic field color alert*
RF strength digital reading
RF Strength indication area
LF Electrical field color alert*
Electrical field indication area
LF electromagnetic field color alert*
Magnetic field indication area

Color Coded Alert Table (for reference purpose only) see items 16, 19, and 21 above.
Note : Alarm beeper sounds when readings enter the red region.

Conversions
1W/m² = 0.1mW/Cm² = 100μW/Cm². 1mW/m² = 0.1μW/Cm²

Operation

Power ON/OFF

Press the power button to power the meter. The display will show the main measurement screen. If the meter does not power on, check that the batteries are installed correctly and are fresh (see battery installation/replacement section later in this guide).
Press and hold the Power button for 3 seconds to power off the meter.

Data hold (HOLD)
Press the HOLD button to freeze the current readings on the display. The HOLD display icon will appear when this mode is active. To release the data press the HOLD button again.

Electric Field Measurements
The EM450 measures the electric field (Electrical Power) in the atmosphere of the sensor’s surroundings. The sensor orientation is printed on the back of the meter. Perform all tests according to the indicated direction of the electric field sensor. Hold the meter at the bottom and at arm’s length, as shown in Figure 3.

Low Frequency EMF Readings (Magnetic field)

Point the front section of the meter toward the desired electromagnetic field to take a measurement. The meter simultaneously displays the electromagnetic field readings of individual (XYZ) and the aggregated Magnetic field readings.

The aggregated calculation equation is expressed as:

Due to environment related magnetic field factors, this electromagnetic field (EMF) meter may display a reading of under 0.50mG prior to testing. This is caused by the magnetic noise in the environment, rather than meter failure.
The Magnetic and Electric field will also display a bar indicator based on the measured value.
Important : If the sensor is moved quickly, excessive field strength values will be displayed which do not reflect the actual field conditions. This effect is caused by electrostatic charges

Measurement considerations:

Hold the meter at arm’s length.
Point the front face of the meter toward the source of power.
Hold the meter steady during the measurement.
Make several measurements at various locations in the work place or other areas of interest. This is particularly important if the field conditions are unknown.
Pay special attention to measuring the neighboring vicinity for possible radiation sources.
Apart from active sources, those components connected to a source may also act as radiators.
For example, the cables used in diathermy equipment may also radiate electromagnetic energy.
Note that metallic objects within the field may locally concentrate or amplify the field from a distant source.

RF strength meter readings

Point the front face of the meter toward the desired RF field to take a measurement.
The RF signal strength will be displayed with the units of measure set from the menu mode.
The RF strength portion of the display will also show a RF strength history histogram and a bar indicator based on the measured value.

Measurement considerations:

Hold the meter at arm’s length.
Point the front face of the meter toward the source of power.
Hold the meter steady during the measurement

Menu Settings

Momentarily, press the center MENU key to enter the main menu.
Press the right SELECT key to cycle through the list.
Press the left ENTER key to enter the selected option.
Use the right SELECT key to choose the desired setting.
Press the left ENTER key to confirm the setting, the meter will exit the menu unless there are more settings required for the given parameter (as in the SOUND setting); in which case continue using the keys in the same manner as described in this section.
From the Main Menu screen (Figure 4), the MENU key can be used to exit the Main Menu.

Main Menu Option Screen

Brightness: Low, Middle, High
Magnetic unit: Gauss/mG, Tesla/ μT (Used for testing Electrical power (50/60Hz))
RF strength unit: μW/m²-mW/m², μW/cm², mV/m-V/m, mA/m, and dBm (Used for testing RF energy from 50MHz to 3.5GHz)
Language: English, Traditional Chinese, Simplified Chinese, Japanese, Spanish
Power OFF (Auto): NO (OFF), 1, 3, 5, 10, 15, 30 (minutes). Factory default is 5 minutes.
Sound: Enable/Disable when ‘enable’ is selected, the keys/alarm sound menu will open.
Keys: 3 options (1, 2, or 3) represent alternate keystroke sounds.
Alarm: 3 options (1, 2, or 3) represent alternate alarm sounds.
Information: Displays the software version

Battery Installation and Replacement

Battery Installation
Remove the rear battery cover and insert three (3) 1.5V AAA batteries observing correct polarity.
Figure 5 Battery Installation

Battery Replacement
The battery status icon shows low energy when the battery voltage drops below the operating level. See installation instructions above for battery insertion.

Never dispose of used batteries or rechargeable batteries in household waste.
- As consumers, users are legally required to take used batteries to appropriate collection sites, the retail store where the batteries were purchased, or wherever batteries are sold.
Disposal :
- Do not dispose of this instrument in household waste. The user is obligated to take end-of-life devices to a designated collection point for the disposal of electrical and electronic equipment.
Other Battery Safety Reminders
- Never dispose of batteries in a fire. Batteries may explode or leak.
- Never mix battery types. Always install new batteries of the same type.

Specifications

Sensor Type: LF – Magnetic Fields

Range: 20mG /200mG /2000mG, 2μT /20μT /200μT
Display resolution: 0.02/0.1/1
Frequency range: 50/60Hz
Accuracy: ± (15% + 100 digits)

Sensor Type: LF- Electric Field Sensor

Range: 50V/m to 2000V/m
Display resolution: 1V/m
Frequency range: 50/60Hz
Accuracy: ± (7% + 50 digits)

Sensor Type: RF Strength

Range: 0.02μW/m² to 554.6mW/m²
- 0.02μW/cm² to 55.4μW/cm²
- 36.1mV/m to 14.46V/m
- 0.02mA/m to 38.35mA/m
- -51dB to 16dBm
Display resolution: 0.02μW/m², 0.2μA/m, 0.2mV/m, 0.002μW/cm², 2dB
Frequency range: 50MHz to 3.5GHz
Accuracy: ± 2dB at 2.45GHz
Display: 4 digits Triple color TFT display
Sample rate: 6 seconds
Sensors: Triple axes (XYZ) ELF and RF and Electric field sensor
Over range condition: The EM450 is equipped with three individual aerial sensors to measure EMF. Overload indication (OL) applies to all three axes (X, Y, and Z)
Battery: Three (3) 1.5V alkaline batteries
Battery Life: Approx. 8 hours
Alarm: Beeps when readings are in the red display region
Operating temperature and RH%: 5°C~40°C (41°F ~104°F); < 80%RH
Storage temperature and RH%: -10°C to 60°C (14°F ~140°F); < 70%RH
Weight: Approx. 120g (4.2 oz.)
Dimensions: 115 x 60 x 21mm (4.5 x 2.4 x 0.08”)