
170 LIGHT AND HEAVY VEHICLE TECHNOLOGY
High—
(a)
pressure
pipe
Spray
chamber
Sight tube
Table outlet
Hand lever Tank Filler cap
Figure 8.37 Two types of injector test unit: (a) Hartridge (b) Merlin
nozzle. A timer is then used to compare, against specifi-
cation, how long it takes in seconds before wetting
becomes visible at the nozzle tip, and also the rate in
number of drops per minute at which back-leakage is
occurring from the nozzle return line orifice.
A note of caution is necessary concerning injector
nozzle testing - In no circumstances must a bare hand be
allowed to get in the way of a fuel oil jet, which can
penetrate deeply into th ...