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NF-5053 shows lower readings then other meters  

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Moderator
(@moderator)
Member Admin
Joined: 11 years ago
Posts: 1048
20/02/2014 12:57 pm  

We have one request from a customer which was purchasing a Spectran 5035 unit and he can see a difference of 50% regarding the reading measurements done with two different units.
How can we explain this difference, do you have recommendations for the customer to make a good test, perhaps there is one parameter to adjust on the Spectran unit?
For your information, the customer is working at 50Hz

The lower reading of the NF 5035 result because of 5 main issues:
a) You are comparing a SPECTRUM ANALYZER (NF-5035) against a BROAD BAND meter: BROAD BAND meter also get influenced from harmonics or even other signals/frequencies so they might show higher readings.
b) Your sample time of the NF-5035 for sure is to low, if you use the standard hotkey. Those settings are only for fast signal detection not for accurate power measurements. Rise it to maximum (3000mS) to get correct (higher) readings.
c) You might use the wrong attenuator with the NF-5035 which can result in TO LOW readings. Try changing it to 20dB, 30dB or 40dB (see notes at forum viewtopic.php?f=31&t=762&start=0&hilit=attenuator)
d) You are not placing the internal 3D sensor of the NF-5035 to EXACTLY the same position as the sensor of the broad band unit. This can give you HUGE differences in readings. For better results matching use a MUCH higher distance to the source, this will reduce the placing error a lot.
e) You are comparing TRUE RMS detector (NF-5035) against simple RMS. This will also result in “to low” readings.

All in all its quite interesting that you "only" get this little difference :D

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mrmc
 mrmc
(@mrmc)
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Joined: 8 years ago
Posts: 25
21/02/2014 2:41 pm  

Which one is the difference between "TRUE RMS" and "SIMPLE RMS"

Thanks


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Moderator
(@moderator)
Member Admin
Joined: 11 years ago
Posts: 1048
21/02/2014 4:14 pm  

How about Google....

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