HW V4 / © 2005 – 2013 Aaronia AG, DE-54597 Strickscheid
48
Manual Spectran V4
Correct measurement
7.6.
Measurement inaccuracy
Aaronia states a typical accuracy for each Spectran model.
However, this means that higher deviations are entirely
possible. Especially when you approach the so-called noise
floor or the maximum sensitivity of a spectrum analyzer,
accuracy decreases by principle.
Even though Spectran instruments offer an impressive
accuracy considering their price, a yet higher measurement
inaccuracy than the base instrument itself has is assumed in
practice: The reason behind this are further factors which
can influence measurement inaccuracy: Some of them are:
temperature dependence, repeatability, antenna errors,
modulation dependence etc.
According to BUWAL (see also
www.BUWAL.ch
), one
should always expect an extended measurement inaccuracy
of at least 35 % even with absolutely professional
equipment. So, expressed in dB, you should always expect
a r/- 3 dB and sonsider this in every measurement.
Example: You measure a value of -45dBm. So, the actual
result could, according to the mentioned measurement
inaccuracy, vary between -42dBm (-45dBm +3dB) and -
48dBm (-45dBm – 3dB). Thus, as you want to measure
exposure due to radiation, you should always assume the
highest value, namely -42dBm..
