» Frequently Asked Questions NARDA PMM   EHP-200

  • We should make a measurement on electrical equipment(electric scalpel, tecartherapy, radiofrequency ablation..)
    The frequencies involved are approximately 250 kHz- 4 MHz. Since it won’t be easy to predict which component of the field prevails on the other, the thing to do would be to measure both of them.
    The instrumentation that we have (EHP-50 and ELT-400) won’t be very useful (only in some cases we will use ELT-400).
    The natural candidate seems to be EHP-200 but I would like to understand what kind of response we can give in the presence of irregular wave forms. I’d like to understand if i could have similar problems with EHP-50 in the presence of fast transient and/or complex wave forms.

    With EHP 200 probe you can measure both components (electric and magnetic) and display them simultaneously on the spectrum of PCs.
    There are no particular problems in measuring continuous interferences such as those issued by the electrosurgical.
    If the disturbance is "damped single pulse (for example, resistance welders) with a few micro seconds rise time we could not see anything.
    In this case, it is suggested to make the measurement with ELT-400 connected to an oscilloscope with an analog RS-232 cable.

  • In the folder "Mode"of the EHP-200 software when select "magnetic mode A " or "magnetic mode B ", the full scale of the frequencies should increase from 3 MHz to 30 MHz? Right?

    magnetic mode B can increase up to 30 MHz
    A magnetic mode can increase up to 3 MHz
    By going from B to A the fStop mode is reset to 3 MHz ,only if in mode B it was bigger than 3 MHz

  • I have some problems in turning the devices on, I can do that only by connecting them to the charger

    To turn on all the 50X-type EHP, EHP-200, OR-02, OR-03 probes you have to be confident and impulsive..
    To turn them off exactly the opposite or hold the button for 5 seconds and then release it.
    This is motivated by the fact that the circuit breaker mounted on these devices is capacitive.

  • Reading the specifications of the instrument I can see that it is possible to set the span from 0 to "Full Span" when I try to set the span to zero, this setting was not implemented, but instead, it automatically changes the span to a higher value. What I would like to know is if it’s possible to set a zero span (known as CW) with EHP200, with the consequent possibility of observing the received signal in RBW band and time domain

    It is not possible to set the span to zero at a certain frequency to be analyzed in order to observe it in base time

  • Is the detector used in "free scan" mode a peak detector? In this case, when the tool performs the integration of all the values in a certain span to give the total value of the field, what kind of operation is carried out?

    The measured value has to be seen as a "instantaneous measurement" or "instant reading" about to peak, BUT NOT a true peak detector; is defined by us as "a sample of that moment."

    - it Makes the quadratic composition of rms values retrieved from the detected peak values