Drawing Number: 21086
Revision: NR
OPERATION MANUAL FOR
CONFORMAL BALLISTICS PRESSURE SENSOR
Series 117B
1
1.0
INTRODUCTION
The Model 117B Conformal Sensor measures
pressure inside metallic cartridges and paper or
plastic shotshell, during firing of the round, without
drilled holes in the round.
The sensor is mounted flush with the chamber walls,
matching the curvature exactly. The expanded
cartridge or shotshell transmits forces through the thin
wall to the sensor.
The Model 117B is a conventional charge output
type sensor using synthetic quartz as the piezoelectric
sensing material.
An alignment guide now standard on all 117B
Models, simplifies installation by automatically
controlling rotational alignment of the sensor, leaving
only the depth adjustment consideration.
2.0
DESCRIPTION
Refer to enclosed installation drawing for outline
dimensions and physical description.
The basic sensor is a probe design with captivated
hollow
clamp
nut.
The
clamp
nut
rotates
independently of the probe body and serves to lift the
sensor out of the mounting port as it is unscrewed.
The alignment device consists of a pin and slotted
clamp assembly which fits tightly over the collar of
the sensor.
The hardened steel pin is accurately aligned with the
axis of the diaphragm curvature and when assembled
into a precisely drilled mating hole in the barrel or
calibration chamber, achieves near perfect rotational
alignment of sensor diaphragm.
The slotted clamp arrangement allows for tolerance in
the location of the guide pin hole in an axial direction
on the test barrel or calibration adaptor.
The precise depth adjustment is obtained by the use
of the correct thickness spacer selected from a set of 9
spacers of various thicknesses supplied with each
sensor.
Once the proper thickness spacer is found, removal
and re-installation now becomes a routine matter.
3.0
INSTALLATION
3.1
PORT PREPARATION
Prepare mounting port in accordance with installation
drawing 117-20 (XX)-90 supplied as part of this
manual.
NOTE: The installation port for the 117B is identical
to that for the 117A.
Drill guide pin hole as shown in installation drawing,
paying particular attention to locating C/L of hole
exactly on C/L of barrel.
Do not use a drill that is worn, as this may cause the
hole to be slightly undersized and the guide pin may
bind as it is drawn into the hole.
It is extremely important that the guide pin hole be
drilled parallel to the sensor mounting port to permit
the guide pin to move freely into the hole.
NOTE: Each model variation of the 117B is designed
to fit in a specific location (measured from the bolt
face) on a specific ammunition caliber. Changing
location and/or caliber will cause a mismatch of
diaphragm curvature with cartridge case diameter
since most cartridge cases are tapered.
3.2
INSTALLING THE SENSOR
After mounting holes have been prepared, proceed
with installation as follows:
1.
On most models of 117B, it is not important
which side of the sensor is mounted toward
the muzzle.
However, on certain types of ammunition
(such as 20 mm cannon) which have a severe
taper, the diaphragm has a matching taper in