User guide

AMP1A Series User Guide

Internal Switch Settings

Peak Hold

The Peak Hold - Manual setting allows the bar graph display meters to

indefinitely maintain the peak hold value until you reset it, either by

pressing a reset button (a special option specified at time of order) or by

removing power and then reapplying power to the unit (unplug/

replug power cord). Contact Wohler Technologies for more

information about this feature.

PPM Characteristics

The PPM characteristics determine the integration time (rise time) and

return time (fall time) of the level meter. The integration time is the

time it takes for the lighted segments of the level meter, after

application of a 5 kHz tone at a certain reference level, to rise within a

specified number of dB of that level. Return time is the time it takes for

the lighted segments of the level meter to fall a certain number of dB

after removal of a 5 kHZ tone of a certain reference level. The PPM

characteristics available for selection using DIP switch sections 7 and 8

of the 10-position Internal DIP Switch (Figure 1–12 on page 17) are

listed in Table 1–4 below.

Phase Correlation Display

Since it is sometimes helpful to observe phase relationships between

two signals being monitored, you can enable the phase correlation

feature within the lower section of the existing bar graph pair in the

AMP1A-30. This feature is enabled by setting a switch on the internal

10-position DIP switch module located internally on the PCB. See

Figure 1–13 on page 18 for DIP module location, and Figure 1–12 on

page 17 for settings. The labels for this feature (see diagram below) can

be specified at the time of order or requested from Wohler for

application to existing units.

Table 1–4 PPM Ballistics and Integration/Return

Time Relationships

PPM Ballistics Integration/Return Times

IEC268-10, Type 1

Integration (Rise) Time is 5 ms (-2 dB);

Return (Fall) Time is 1.7 seconds (20 dB)

IEC268-10, Type 2

Integration (Rise) Time is 10 ms (-2 dB);

Return (Fall) Time is 2.8 seconds (24 dB)

DIN 4506

Integration (Rise) Time is 5 ms (-2 dB);

Return (Fall) Time is 1.5 seconds (20 dB)

Single Sample

Integration (Rise) Time is a single sample;

Return (Fall) Time is 1.5 seconds (20 dB)