Tabla de contenido
Publicidad
46
1.
If no more experiments are to be conducted and the data storing process has been finished
ready to be transferred to a computer using the
MicroTrap™
can be switched
5.5 Utilizing The External Trigger
In some data recording applications, it may be desirable to have
the
MicroTrap™
begin to record exactly when a specific external
event occurs. For the specific event to trigger the MicroTrap™, and
subsequently correspond to time zero on the graph, the
port is used.
The
EXT TRIG
function operates on the simple concept of
BREAK
circuits. Both types of trigger capitalize on the fact that the
EXT TRIG
port outputs a constant voltage after the
pressed. The traditional
MAKE
circuit is closed by the event of interest, even if only momentary. The
traditional
BREAK
circuit is triggered when the complete circuit is
broken, even if only momentary.
To create a
MAKE
or
BREAK
(two wired) cable to the adaptor. A good example of a duplex wire that is fit for duty as a trigger line is the lead line used for initiating
electric detonators in the field.
An example of a
MAKE
trigger would be to twist the duplex wire with itself, leaving the insulation on each wire, and then run it over the
tip of a detonator or around a section of detonating cord, so that upon detonation of the explosive, the insulation is stripped and the
two wires are forced into contact with each other under pressure from the explosive. This momentary contact will complete the
circuit and thus trigger the MicroTrap™. The
conductive plasma in the vicinity of the detonation front, that will assist in arcing the current from one wire to the other.
An example of a
BREAK
of interest, and then twist the bare ends of the wires together so as to complete the circuit. When this object deforms or expands, the
wires will disconnect and cause the circuit to open - triggerin the MicroTrap™. Beware that even a momentary break in the trigger circuit
will cause the
MicroTrap™
The procedure for using the
Chapter
1.4.
OFF
and the data will remain in the
START
circuit is triggered when the open
trigger using the
EXT TRIG
MAKE
trigger is especially dependable because the explosive itself generates an electrically
trigger would be to wrap a duplex wire around an object that is expected to deform or expand during the event
to trigger. Avoid disturbing a
MREL Data Acquisition Suite
M i c r o T r a p ™ M a n u a l d e O p e r a c i o n e s - E d i t i o n 3 . 0
Software
as detailed in
Section
MicroTrap™
EXT TRIG
MAKE
or
button is
port, connect a
BNC Adaptor
BREAK
trigger once the
to program the
MicroTrap™
(Step 11
above), then the data are
6.1. If data transfer is to be conducted later, then the
non-volatile memory.
to the port and subsequently connect a "duplex"
START
button has been pressed.
for
or
external triggering is detailed in
MAKE
BREAK
MAKE
Publicidad
Tabla de contenido
