Manual

Page 33
There is no difference between Peak Hold and Peak Follow in the
Dry Contact range.
5.5.8 Disconnect the test leads from the circuit under test and
return the Range Switch to the OFF position.
5.6 Measuring DC Pulse Code Signals
5.6.1 Overview
The DC Amps function has selectable polarity. This is useful for
measuring the transmit and receive currents in pulse coded track
circuits. The selection of the polarity is made via the Signal Select
Switch. In any other DC function (DC Volts or DC mA) the position
of the Signal Select switch has no affect. The polarity of pulse coded
signals cannot be selected in the DC Volts or DC mA functions.
5.6.2 Selecting the Polarity
To measure transmit and receive currents, see Section 5.3 in the
Instruction Manual. Place the Signal Select switch in the +/- posi-
tion (for Test Sets without Cab Filters) or in the AP +/- position (for
Test Sets with Cab Filters). The peak level and timing parameters of
the highest amplitude signal are now automatically measured. To
select a particular polarity (transmit or receive) to measure, simply
change the Signal Select switch to the + or the - position. That
signal will be captured. If the signal is of the opposite polarity (e.g.
a positive signal when the switch is set to -) the pointer will deflect
down scale. On Test Sets with Cab Filters, the + and - positions of
the Signal Select switch are also labeled with the Cab frequencies
applicable to that Test Set.