Status Indicators; Smoke Flow Control; Flow Meter - Bosch SMT 300 Original Instructions Manual

en 26 | SMT 300 | Product description
4.5.2

Status indicators

LED Status Status
Green light When connected to the vehicle battery
Battery
12 V.
Flashes Low voltage supply.
+ -
(1x per s)
ON/OFF Red light SMT 300 switched on.
Off SMT 300 switched off.
SMT 300 must be connected to vehicle battery 12 V.
1)
4.5.3

Smoke flow control

A smoke flow control with different settings is located
on the front of the SMT 300.
Fig. 2: Smoke flow control in setting "TEST"
Adjustment Description
"TEST" The system to be tested is filled with
"smoke-free" air.
This setting yields the most accurate results
from the flow meter and is used to test nu-
merous systems where no smoke is re-
quired (e. g. solenoid valve operation test).
"FLOW CONTROL" The smoke flow rate can be adjusted to any
... "SMOKE" value. Localizing the source of leakage is
frequently simpler at a low smoke flow rate.
"SMOKE" SMT 300 produces maximum amount of
smoke flow
i
Check for leakage with the unit set to "TEST".
i
The smoke flow control has no effect on the pres-
sure in the smoke supply line, but affects only the
smoke flow rate.
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4.5.4
The flow meter has two reference points with the aid
of which the extent of leakage in the system being
tested can be classified (based on the manufacturer's
specifications). The reference points 0.25 mm (0.010"),
0.5 mm (0.020") and 1.0 mm (0.040") correspond to
the leakage requirements when testing an EVAP system.
1)
The ball in the flow meter shows that flow is occurring.
1)
The higher the ball, the stronger is the flow. This is why
the ball moves upward when filling the system to be
tested (see fig. 3).
i
The system being tested can be considered filled
when the ball in the flow meter no longer drops
during the leakage test or when the pressure on the
pressure indicator no longer increases.
If the ball in the flow meter drops to the bottom after
the closed system to be tested is filled, this means that
nothing is flowing and there is thus no leakage in the
system being tested.
If there is an indication of flow in the flow meter even
after the system is filled, this indicates the existence of
leakage. The higher the position of the ball in the flow
meter, the greater is the leakage.
2
1
Fig. 3:
1 Ball in the flow meter
2 Reference points for the extent of leakage (scale in mm and
inches)

Flow meter

Overview of the flow meter
Robert Bosch GmbH