-
Make sure that all connections
are made with clean bare wire ends and if necessary freshly
exposed bare wire
-
Make sure that the insulation
of the leg wires is intact and not damaged by rough handling
during charging, stemming etc.
-
Insulate all joints in wet
conditions to arrest the leakage of applied firing current.
-
Make sure that the leg wires
are sufficiently long to allow adjacent holes to be joined without
use of additional connecting wires.
-
Test the shot firing cable
for continuity and insulation before using in the circuit.
-
Make sure that the bare ends
do not come in contact with any conductors such as power lines,
pipes, rails or other paths of stray current.
-
Make sure that the blasting
circuit is not in the immediate vicinity of any electrical equipment
during shotfiring. The stray current may fire off normal electric
detonators.
-
Ensure the usage of delay
numbers in desired sequence in the blast.
-
Make sure that all persons
were withdrawn to a place of safety before connecting shotfiring
cable to the circuit.
-
Make sure that the shotfiring
cable is connected to the exploder just before firing the shot
and is immediately disconnected after the shot is fired.
-
The exploder key must always
be in the possession of the blaster and not kept on the machine.
-
Ensure that the exploder used
is of adequate capacity and the current is of the desired magnitude
for full initiation of the round.
-
Make sure that the excess
leg wires are neatly coiled and the connections are not getting
earthed anywhere.
-
Check the circuit for continuity
before firing the shots. This must be done using only with approved
blast- ohm-meter.
-
Ensure that the shotfiring
cable is of adequate length for firing from a point of safety.
-
Make sure that no person approaches
the blast site until it is cleared of the fumes and inspected
for safety.
-
Always take a shelter before
firing the circuit.
TESTS DONE
FOR SAFETY IN HANDLING AND USAGE
(1) Drop Test
: Drop test is a measure of the
capability of the detonators to remain safe without going off
even when it is dropped vertically with the open end above a hard
surface like steel plate or concrete slab. Dropping height used
in the test is 2.5 meters. This ensures the safety while accidental
dropping of detonators in the field onto the ground.
This test is applicable to all types
of Detonators.
(2)
Shake Test :
Shake test is a measure of the ability of the detonator to withstand
without going off the disturbance caused to it by thump, vibration
and shock, similar to the ones that are experienced while being
transported on rough roads.
The test is carried out by keeping the detonators in a box and
allowing the box to fall from a height of 15 cms at the rate of
30 times per minute for a period of 5 minutes.
This test is applicable to all types of Detonators.
(3) Snatch
Test : Snatch test is a measure
of the ability of the fusehead to withstand, without going off,
the friction caused to it by a sudden severe pulling of the lead
wires.
A sudden, pulling-down dead load of 5 kgs over a free fall of
0.5 mtrs is applied to the ends of legwire through which the friction
to the fusehead is caused.
This test is applicable to all types of Electric Detonators.
