User's Guide RF EMF Strength Meter Model 480836 99 Washington Street Melrose, MA 02176 Phone 781-665-1400 Toll Free 1-800-517-8431 Visit us at www.TestEquipmentDepot.com Back to the Extech 480836 Product Page Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 FAX 781.665.0780 - TestEquipmentDepot.
1.0 - Safety Information CAUTION • Before making a measurement, check if the low battery symbol ( + shown on the display when the meter is switched on. Replace the battery if the symbol is displayed. ) is • In the case of prolonged storage, it is preferable to remove the battery from the meter. • Avoid shaking the meter, particularly in the measurement mode. • The accuracy and function of the meter may be adversely affected by exceeding the specified limits as well as by improper handling.
2.0 - Introduction 2-1 Fundamentals Electromagnetic Radiation This meter is used to indicate radiated electromagnetic fields. Wherever there is a voltage or a current, electric (E) and magnetic (H) fields arise. Examples include the electromagnetic fields from radio broadcasting and TV transmitters. 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.
2-3 Features This meter is a broadband device for monitoring high-frequency radiation in the range of 50MHz to 3.5GHz. The non-directional electric field and high sensitivity also allow measurements of electric field strength in TEM cells and absorber rooms. The unit of measurement and the measurement types are expressed in units of electrical and magnetic field strength and power density. At high frequencies, the power density is of particular significance.
3.0 - Specifications 3-1 General Specifications • Measurement method: Digital, triaxial measurement. • Directional characteristic: Isotropic, triaxial. • Measurement range selection: One continuous range. 2 • Display resolution: 0.1mV/m, 0.1μA/m, 0.001μW/m , 0.001μW/cm 2 • Setting time: Typically 1s (0 to 90% of measurement value). • Display refresh rate: Typically 0.5 seconds • Display type: Liquid-crystal display (LCD), 4 digit. • Audible alarm: Buzzer.
3-2 Electrical Specifications Unless otherwise stated, the following specifications hold under the following conditions: • The meter is located in the far-field of a source, the sensor head is pointed towards the source. • Ambient temperature: +23℃±3℃ • Relative air humidity: 25% to 75% Sensor type: Electrical field (E) Frequency range: 50MHz to 3.5GHz Specified measurement range: • CW signal (f > 50MHz): 20mV/m to 108.0V/m , 53μA/m to 286.4mA/m, 2 2 1μW/m to 30.93W/m , 2 2 0μW/cm to 3.
4.0 - Operation 4-1 Front Panel Description (1). E-field sensor. (2). LCD display. (3). MAX/AVG/↵ key : c Press this key to scroll through the following: “Instantaneous”→ “Max. instantaneous” → “Average” → “Max. average”. d In the read mode, press this key to exit. e In the alarm setting mode, press this key to store the setting value. f Press and hold this key while turning the meter on to disable the audible sound. The “ ” symbol will disappear. (4).
4-2 LCD display description (1). : Auto power off function on / off. (2). : Audible sound function on / off. (3). MAX: Maximum measured value displayed. MAX AVG: Maximum average value displayed. (4). AVG: Average measured value displayed. (5). + : Low battery indication. (6). Units : mV/m and V/m : Electric field strength. μA/m and mA/m : Magnetic field strength. 2 2 2 μW/m , mW/m and μW/cm : Power density (7). (8). (9). : Measured value displayed as per selected mode and selected units.
4-3 Using E-field sensor The 3-channel sensor is located at the top of the meter. The three voltages generated by the sensor are fed back to the meter. In far-fields, an E-field sensor is preferable due to the greater bandwidth. The E-field sensor frequency ranges from 50MHz to 3.5GHz. The meter is a small portable instrument that measures the electric field in the atmosphere of the sensor’s surroundings.
4-5 Setting the meter 4-5-1 Setting the units of measurement Use the UNIT key as follows. (a) (b) Z Z UNIT XY XY UNIT UNIT (c) (d) 2 Z 2 Z UNIT XY XY (a). Electric field strength (V/m). (b). Computed magnetic field strength (mA/m). 2 (c). Computed power density (mW/m ). 2 (d). Computed power density (μW/cm ). 4-5-2 Setting the result mode Instantaneous result mode is automatically set when the meter is turned on.
4-5-3 Setting the alarm limit value (ALM) 2 2 MEM ALARM READ MEM READ MEM READ MEM READ 2 MEM 2 READ 2 MEM 2 READ MEM READ MEM READ key to turn off the meter. 1. Press key to turn on the meter, the display 2. Press and hold the MODE key, then press then shows “ALM” and “▲” (The Alarm setting mode). The four flashing digits can now be changed. 3. Press ▼ or ▼ key to increase or decrease the value. 4. Press ↵ key to store the new setting value and exit. 11 480836 V2.
4-5-4 Switching the alarm function on or off ALARM ALM ALM 1. Press ALARM key for 2 seconds to switch the alarm function on or off. The “ALM” and “ ” symbols in the display indicates that the alarm function is on. 2. When the alarm function is on, the display will show “▲” if the instantaneous measured value exceed the limit value. 4-5-5 Setting the audible sound function off When the meter is normally turned on, the audible sound function is on. key to turn off the meter. 1. Press 2.
4-5-7 Setting the backlight auto off function off UNIT 1. Press key to turn off the meter. 2. Press and hold key and turn on the meter again to disable the backlight auto off function. 4-6 Making measurements 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. Recommendation: Hold the meter steady during the measurement.
4-7 Storing readings The meter includes a non-volatile data memory that can store a maximum of 99 measured values. 4-7-1 Storing individual measured values MEM The current memory location number appears in the lower right small display. Once you press the MEM key, it will store a displayed value and increment the memory location by one. Each flash of the “ ” symbol display indicates one reading has been stored.
4-7-3 Deleting stored values Once the memory is full, the entire contents of the memory can be cleared. MEM READ 1. Press MEM to turn off the meter. 2. Press and hold MEM and turn on the meter again; the display will shows: “ ” and “ ”. 3. Press ▼ to select “ ”. 4. Press ▲ to clear memory. 5.0 Battery Installation and Replacement 5-1 Battery Loading Remove the rear battery cover and insert a fresh 9V battery.
