1) How to hold
the CORNET meter for measurement?
The CORNET meter has three internal sensing antenna built in to measure
the received signal; the user should not cover or block the sensor area
of the meter while measuring. The location of the sensors is indicated
on the meter's back silver label. The CORNET meter is a single axis
meter; please rotate the meter to get the maximum reading direction and
follow that direction while measuring. (Only a single axis meter can
find the direction of the signal source.) The meter has three operation
modes (RF, LF Gauss, and LF Electric field); please follow the
directions in the picture below while doing the measurement.
2)What is the best measuring distance between the RF source and the meter?
majority of RF safety standards required a minimum measurement distance
of 1 meter or 3 meters from the source of the RF signal; otherwise, the
meter will become overloaded (such as RF transmitter or WIFI router
which radiates very high RF power from its transmit antenna).
If the meter is placed too close to or right next to the transmit
antenna, the frequency counter feature of the meter will also get
For mobile phone antenna tower measurement:
The area between 50 and 300 meters from the antenna tower is the one with the largest radiation risk
When the distance was extended, the RF radiation rapidly reduced ( by distance square)
The RF transmit power to the transmit antenna on the tower also affect the radiation level as well.
Radiation power density (mw/m2)= RF transmit power(mw)/4πR2 where:R is distance from RF source
*A highly recommended resource on cell tower radiation may be found at:
http://www.buergerwelle.de/assets/files/workshop on cell tower
Accuracy of the meter?
Each CORNET meter is
calibrated in our USA lab using certified test equipment before being
shipped to our customers.
We also compare the meter's
reading to that of an industrial standard certified professional EMF
meter from companies like Narda and Smartfield meter to make sure it is
correct. The meter store the Calibration data inside the meter's
memory, therefore it is not required to re-calibrate the meter from
time to time.
4)What is the
Maximum frequency the ED88TPlus meter can operate?
ED88TPlus5G and ED88TPlus2 meters
have an 8GHz specification, but they are found to work up to
11GHz with reduced
as a detector purpose, such as detecting a microwave
motion sensor for LED light control detection. (For better
sensitivity the ED85EXPlus meter with LPDA1810 external antenna unit is
* Remember that the air loss of a high band microwave signal
is very large; most devices at that frequency operate at a signal level
of -80dBm to -100dBm; you may need to place the meter very close to the
signal source to detect it.
is the Frequency counter function of the ED88TPlus series meter ?
Real time Frequency counter
ED88TPlus series meter is currently the only meter on the market with a
built-in frequency display function.
The ED88TPlus series meter's
Frequency display function is a real time
frequency counter; the meter measures both the RF signal level and the
frequency of the received signal at the same time, down to each
pulse/burst level ( the pulse/burst
can be as short as
operates up to 4.2GHz,
covering all 5G mobile
network frequency bands (except the
millimeter wave band), while the ED88TPlus2 and previous
models of CORNET meters operate up to 2.7GHz.
Based on the frequency of the signal, the user can determine the source
and type of the RF signal.
(for example: Wifi use 2.4GHz, DECT
phones use 1.9GHz, 4G cell phones use
1.7GHz-1.9GHz, cordless phones, IOT devices use 900MHz, and 5G
mobile network uses 3.5GHz....) Once
the signal source type is known, it is very easy to find a way to
reduce the RF radiation level.
signal level is required
to correctly detect the frequency of the signal.)
6) The difference between RF power (dBm, mw) and RF power density (mw/m2) ?
-The dBm or mw is the unit of the received RF power. (0dBm=1mw)
-The mw/m2 is the unit of the RF power density which is related to the RF field strength.
-The RF power density (mw/m2) is the received RF power (mw) divided by the area (m2) of the the effective area of the meter's receiving antenna.
For example: tne meter's antenna received the RF power of -25dBm, after divided by the effective area
of the receiving antenna (m2) we got the power density or field strength of 1.8mw/m2
The effective area of the receiving antenna is different for different antenna or meter design.
If you are measuring RF field strength you use the unit of RF power density (mw/m2)
If you are measuring received RF power you use the unit of RF power (dBm)
*most of the RF engineer uses dBm because the RF transmitter
output, antenna loss, on air loss, distance loss, and frequency loss
etc., ... are all specified as dB or power of dBm. ( the meter's received RF power is the RF source tranmitted power minues all these loss).
Compare Frequency counter to the Spectrum Analyzer?
Spectrum Analyzer problems in modern
digital RF environment
modern digital RF signal utilized
in mobile phones, Wifi, and new wireless devices is a pulse/burst kind
of RF signal. It transmits signals in extremely short bursts but does
not send any signal in between the pulses/bursts; the RF pulse/burst
has a very high signal level while bursting, and practically little
signal during non-bursting time. The classic scanning method of
Spectrum analyzer has a very sluggish scanning speed because it scans
each frequency of the covered frequency spectrum step by step. It
displays the frequency when the incoming signal frequency
is matched with the spot scanning frequency of the Spectrum analyzer.
It is a "Hit or Miss!"
procedure. It is fine for old continuous
analog RF signals, but not for modern digital RF pulse/burst type of
The classic scanning type of
Spectrum Analyzer simply cannot record the
receiving on and off RF burst in time (It will take several seconds to
low frequency of spectrum to high GHz of spectrum in old scanning
type of Spectrum analyzer). Because the on-air RF signal is
asynchronous to the spectrum analyzer's scanning operation, the
Spectrum analyzer will miss burst signals most of time.
method to avoid the issues is to repeatedly scan the full frequency
spectrum again and again then overlay the findings in the goal of
obtaining a complete
image of the spectrum of the signal received. Most of the time, this is
not very effective because the digital RF transmitted signal bursts are
time dependent and never repeat themselves like continues wave analog
RF signals, If the Spectrum analyzer fails to capture it at the
scanning frequency in time, the RF burst signal is gone and the
Spectrum analyzer will never able to capture it again and show the
frequency of it.
To solve the problem,
modern Real-time Spectrum Analyzer captures sections of the
frequency spectrum all at once and then display the spectrum using
digital signal processing methods, but it is very expensive and bulky
equipment, the bandwidth of the section of frequency that the
Spectrum Analyzer can capture each time currently is also very limited.
slow scan speed of Spectrum analyzer can not capture the fast on/off
pulse/burst of the modern digital RF signal in time. The
real time frequency counter in the ED88TPlus series of
meter is the best solution for the modern digital RF
ED88TPlus5G meter captures
signals at a rate of 25000 samples per second, allowing it to record
digital RF signal pulses and bursts as short as 100usec. Each
pulse/signal burst's level and frequency are recorded in real time. You
always get the correct signal level and frequency of the signal
* (The frequency counter circuit requires a certain
minimum signal level to function properly.)
5G mobile frequency indicator?
5G mobile frequency frequency
The ED88TPlus5G meter
frequency counter display supports
frequencies up to 4.2GHz. The meter automatically detects the 5G mobile
network frequency bands signal and displays a =5G=
mark on the display to indicate the
detection of the 5G mobile network frequency. (5G channel
n5, n71, n77, and n78)
(*A minimum signal level is required
to correctly detect the 5G signal.)
How to use the ED88TPlus5G to measure the 5G signal?
5G mobile network can transmit data at super-fast speeds.
consumes a lot of bandwidth from the system, limiting the number of
services that can be provided at the same time. There are two types of
5G network systems: SA (standalone) and NSA
(no-standalone). The SA
system employs a pure 5G network system and frequency. The NSA
combines the older 4G-LTE system and frequency with the new 5G network
system and frequency as a hybrid system.
Because the SA system is very expensive, 99 percent of the world's 5G
mobile networks are now using the NSA 5G system..
When a mobile handset attempts to connect to a 5G antenna tower-based
station, the NSA 5G system uses the older 4G-LTE frequency band for the
protocol handshaking phase. and it only transmits super high-speed data
using the 5G system/frequency band during the 5G data download phase.
It is done dynamically. If the based station decides that the 5G
signal is not good enough or is too busy, the NSA 5G system may not use
the 5G system/frequency at all in the data download phase of
transmission. Instead, it may use the older 4G-LTE system/frequency for
data download phase transmission. As a result, the 5G network signal
will not be visible in the NSA 5G system all the time.
not be able to detect the 5G signal/frequency in front of the 5G
antenna tower in the NSA 5G system, unless someone in the area is using
the 5G phone talking to the antenna tower base station, and is in the
5G data download phase using the 5G signal/frequency.
ED88TPlus5G has a built-in frequency counter and 5G frequency indicator
that supports all 5G frequency bands*. It will detect and display the
5G signal frequency when the NSA 5G system transmits the 5G signal with
the 5G frequency during the 5G super high speed data download phase.
Other meters without a frequency counter function will not be able to
tell you whether you are measuring an old 4G/LTE signal or a new 5G
*except the millimeter wave band
Statistical Data window of the received RF signal in ED88Plus5G ?
Modern digital RF
signals are pulse/burst signals with a very high on-time burst signal
and almost no signal in non-bursting time. It is different
from the traditional continuous wave analog type of RF
Today, the majority of wireless devices use digital
The "Average value" of the signal
level used by the transitional
EMF meter or RF power meter to display the level of a continuous wave
RF signal does not work well for modern digital RF signals, because the
digital RF signal changes on and off so fast that the "average value"
can no longer show the actual behavior of the signal measured.
The majority of the professional
RF power meter is now operate in peak power meter mode. It displays the
peak level of the RF pulse/burst signal. EMF safety research is also
expanding into the digital RF field.
the peak value is good enough for the modern digital RF signal
Since the ED15 meter,
meter has been a peak power meter. But, is the peak value reading
adequate for modern digital RF measurement? The answer is no, not
really! The modern digital RF
signal burst is
changing so fast that you
can have several thousands of RF burst signals coming during the
standard 0.5sec LCD screen update period. A single peak value of an RF
pulse/burst signal among thousands of pulse/burst signals cannot
represent the true behavior of the received signal. It
Statistical data from all of these thousands of pulse/burst signals to
show the actual behavior of the received signal.
(* Why is the screen updating time 0.5 seconds? It is the
of time that the human eye can keep up with the fast-changing reading
on the LCD display screen. You can't read it well if the screen updates
faster than 0.5 seconds.)
The ED88TPlus5G meter samples the
signal at a rate of 25000 samples per
second, with 12500 samples available for each 0.5second screen update
period. 12500 samples are divided into seven bins (+5 to -5dBm, -5 to
-15dBm, -15 to -25dBm, -25 to -45dBm, -45 to -55dBm, -60 to -65dBm). It
shows the actual real-time signal level distribution within 0.5 seconds
and is very useful for analyzing digital RF signals with short
burst/pulse ON-time signals and long zero/very low level OFF-time
The 7 sample bins are organized
according to the SBM2008 exposure
recommendation, and the calculated Peak Value, Whole Average
Peak Average Value, MAX value, and Average Pulse-power value are also
shown on the same display window.
(* The Average Pulse-power value is the
average of all signals
above the -60dBm threshold level (0.0005mw/m2, "slight
concern" based on the SBM2008) ; it is the average ON-time power of all
RF burst/pulse for digital burst/pulse type of RF signal).
For example: in the graph below,
9832 samples are below -60dBm and 50
samples are between -25dBm and -45dBm.
(*The number in the Statistical
bins is scaled down by 1.25 to get a total of 10000 for 7 bins, so the
user can calculate the percentage of signals in each level bin by
dividing the number by 100, or simply ignore the last two digits of the
As a result, 0.5 percent of the time the RF
level is greater than -45dBm (SBM2008 exposure 0.01mw/m2 limit "high concern")
98.3 percent of the time it is less than -60dBm (0.0005mw/m2, "slight
concern" based on the SBM2008). This tell you that 98.3% of
the time the RF radiation level is in the "slight
concern" level (based on the SBM2008 recommendation), and
only 0.5% of time it is in the high concern level. This is
the information the information the EMF experts are looking for.
to access and use the Statistical data in ED88TPlus5G?
Very simple and
ED88TPlus5G provides statistical data for all received signals with a
single simple click. When the ED88TPlus5G displays a high reading on
the LCD display, a single button click displays the
all the signal received in the previous 0.5 seconds. The signal's peak
value is also displayed as a Big
character, and the distribution of the 12000 sample data is displayed
in 7 level bins (based on the SBM2008 recommendation). You can
determine whether the signal is of high concern or not by looking at
the distribution of the 12000 sampled data in the Statistical data