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If a FREQUENCY SCALE other than
"x
1 Lin." is required, the calculations must be re-
peated, amending equations 14 and 1 6 I}Y an appropriate factor of 1 0.
The settings are given in Table 4.9.
In practice, it is found that there is a lower limit to the frequency range for reliable analy-
sis with these settings. See section 4. 7 for details.
Bandwidth
AVERAGING TIME
PAPER SPEED
(Hz)
(s)
(mm/s)
3,16
0,3
0,01
10
0,1
0,1
31,6
0,1
1,0
100
0,1
3,0
316
0,1
10,0
1000
0,1
10,0
740196
Table 4. 9
.
Settings for DC Recording of Deterministic Signals with
FREQUENCY SCALE
"x
1 Lin"
4.5. AUTOMATIC BANDWIDTH AND AVERAGING TIME PROGRAMMES
To facilitate the set-up of an analysis system to provide a faster analysis, four pro-
grammes of bandwidth and averaging time switching are provided on the 2010. The
method of their use can be seen from a study of section 4.3 and 4.4. Switching frequen-
cies of the programmes are either decade multiples of 20Hz or 63Hz, or both, as de-
tailed in Chapter 1
.
The objects and uses of the programmes are summarised below.
4.5.1. B & T Variable Programmes
The two programmes (positions
"3"
and
"4"
on the B & T PROGRAM selector) allow the
product of bandwidth (B) and averaging time (T) to be kept constant while progressively
increasing the bandwidth with frequency. This enables the ratio B
2
If to be the same at
the different transition frequencies. For a given bandwidth, the maximum frequency to
be considered is the first switchover frequency. Therefore, the measuring time can be re-
duced considerably without any sacrifice of the relative resolution.
Reference should be made to Chapter 1 for choice of programme for a particular appli-
cable. Reference should also be made to section 3.8.2 on remote control of these pro-
grammes.
4.5.2. T Variable Programme
This programme (position
"2"
on the B & T PROGRAM selector) enables the product (Tf)
to be kept practically constant at the switchover frequencies. The bandwidth (B) is kept
constant at any selected value throughout the measurement.
This programme is of particular use in the study of deterministic signals with discrete fre-
quency components only (the study of harmonic distortion for example).
53
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