Electromagnetic Field (EMF) MeasurementsOption 444 : Spectrum Analyzer : Spectrum Analysis EMF Menu
Spectrum Analysis EMF Menu
Key Sequence: Shift > Measure (4) key > Power and Bandwidth > EMF Measurement
EMF Menu
On/Off: This is the main EMF Measurement On/Off button. Press this key to switch EMF On and Off. The start and stop frequencies must be within the range of the spectrum analyzer and isotropic antenna used, and the antenna must be connected. The detection type is automatically changed to RMS/Avg when EMF is On. It is restored to the previous detection setting when EMF is Off.
Note: You are prompted with warning messages if the antenna is not connected or if the frequency span of the analyzer is outside the antenna range.
Automated Measurements: Opens the EMF Auto Menu where you can set up EMF parameters and start the measurement. EMF must be turned On.
Limits: This is a shortcut to the standard spectrum analyzer Limits menu (Shift > Limit (6)). For EMF measurements, only the upper limit line is used for testing the pass/fail condition. Multi-segment limit lines can also be created.
ICNIRP Limit On/Off: Turning this On creates a limit line consistent with the guidelines of the International Commission on Non-Ionizing Radiation Protection. Trace C contains the averaged isotropic result and is tested against this limit line, and then the Pass/Fail status is updated.
Units: The unit choices are dBm/m2, dBV/m, dBmV/m, dBuV/m, V/m, W/m2, dBW/m2, A/m, dBA/m, W/cm2. dBm/m2 is the default.
Trace: Opens the Trace Menu.
Back: Returns to the Power and BW Menu.
EMF Auto Menu
Key Sequence: Shift > Measure (4) key > Power and Bandwidth > EMF Measurement > Automated Measurements
EMF Auto Menu
Measurement On/Off: Starts the EMF Measurement. The Dwell Time, Measurement Time, and other related parameters must be set before starting the measurement. This button is useful for stopping or restarting measurements when settings need to be changed. When the measurement is in progress, access to other menus and key presses are blocked. The Measurement On/Off key is then the only key that can be accessed.
Measurement/Setup save is not permitted when EMF Automated Measurement is turned On. At the end of the measurement, the button will automatically be updated to Off and access to all menus restored.
Axis Dwell Time: Specifies the time spent on each axis. The sweeps are averaged and saved for further computation.
Measurement Time: Sets the duration of each EMF measurement from one minute up to 30 minutes. The default is 6 min. For example, if Axis Dwell Time is set to 1 s and Measurement Time is 1 min, you will get one isotropic result after 3 s and approximately 20 at the end of the one‑minute measurement.
The Current row in the summary table at the bottom of the screen displays a running average, max and min of these isotropic results every 3 s. The displayed values are computed from all measurements completed thus far within the measurement time. At the end of the measurement time, the Current row is cleared and the Total row is updated with the max, min, and running average of all isotropic results (20 in this example).
Number of Measurements: Sets the number of EMF measurements to complete from 1 up to 10,000. The EMF test is fully executed when the specified number of measurements have completed.
Auto Logging On/Off: Auto Logging is On by default. This must be selected prior to starting the measurements for the results to be logged. The average, max, and min values of each isotropic set of three axes, the isotropic trace data, and the computed total average, max, and min values are saved in a tab delimited text file in internal memory.
The location of this log file is a new folder named with the current time stamp followed by _1, and created in “/Internal Memory/EMF/”. The folder can hold 100 files. Each file holds five measurements. The 101st file and the files created thereafter are stored in a new folder with the same time stamp as the first, followed by _2 (then _3, and so on). Each file has its own time stamp.
Back: Returns to the Spectrum Analysis EMF Menu.
Trace Menu
Key Sequence: Shift > Measure (4) key > Power and Bandwidth > EMF Measurement > Trace
Trace Menu
Trace: Selects one of three traces, each holding a different result.
Axis: Holds the sweep result for the currently selected axis.
Result: The isotropic result (X2+Y2+Z2)0.5 at the end of an X, Y, Z sweep.
Trace C: Selects Trace C for view and Options setting.
View/Blank: Toggles the selected trace between View and Blank state. Two or all three traces can be viewed simultaneously by selecting each trace and setting its state to View. Selecting Blank will blank the currently selected trace.
Trace C Options: Toggles Trace C Options:
Avg: Holds the average values of the isotropic results from trace averaging (volts on a linear scale). This is the running average of the individual isotropic measurements completed within the specified measurement time.
TMax: Holds the maximum values of the isotropic results over the total EMF measurement period (measurement time x number of measurements). During an active measurement period, the running maximum values are displayed.
Tavg: Holds the average values of the isotropic results over the total EMF measurement period (measurement time x number of measurements). During the measurement period, the running average values are displayed.
Back: Returns to the Spectrum Analysis EMF Menu.