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Why are there two different readings?
The Acoustimeter is unique in the way it displays information about its
measurements. There are two different displayed results showing both
Peak and Average measurements. At first, this may seem confusing. We
believe that it is important to know both when assessing your exposure to
modern telecommunication signals.
Digital and Analogue:
What is the difference?
Many modern wireless devices use a
digital
system of communicating.
This includes Mobile Phones (GSM & 3G/UMTS), WiFi, Cordless phones
(DECT), Digital TV & Digital (DAB) Radio. Many modern digital systems
(such as GSM, DECT and WiFi) turn the signal on and off at high speeds to
represent data, often with long gaps between data bursts. This produces a
non-continuous signal, which we describe as “pulsing”. It is these
amplitude changes that the Acoustimeter allows you to hear.
An analogue signal is a system of communication that is not digital. The
old TV system, most radios, walkie-talkies and hearing aids are examples
of analogue signals. They use a continuous carrier, and instead of turning
“on and off” to represent data, will vary the frequency (FM) or strength
(AM). Analogue TV & VHF FM Radio stations are being phased out over
time.
Typical differences between Peak and Average
With an analogue system, the peak and average levels should be similar,
as the signal is continuously on while it is being used. However, because
most digital systems spend a large proportion of their time not
transmitting, the average level does not represent the actual waveform
even though it is technically accurate as shown in the diagrams below.
Summary of Contents for AM-10
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