Drawing Number: 21105
Revision: NR
OPERATION MANUAL FOR
BALLISTICS PRESSURE SENSOR CALIBRATION ADAPTOR
FOR AMMUNITION TESTING
Model 090B
3
5.
Without
dropping
pressure,
immediately
proceed to next pressure level, set pressure and
record reading.
NOTE:
For sensors with full scale range of
40,000 psi or less, calibration increments of
5,000 psi are used. For sensors with full scale
range above 40,000 psi, increments of 10,000
psi are used.
Proceed in this manner to full scale.
6.
It is important to note that the test pressure must
always be approached from below, i.e. by
increasing pressure, never decreasing.
Use only unfired cases since the hardness of
fired cases may have been altered.
Do not cycle case before calibrating. Take one
set of readings on each case, then discard the
case.
If the test pressure at any point is exceeded by
more than 5%, discard the case and the data and
start over with another case.
8.
Repeat procedure for each case to be
calibrated.
6.0
ORGANIZING THE DATA
Since the family of values of output charge at each
calibration point follows a random distribution about
a mean value, the standard deviation at each point is a
valid indication as to the preciseness of the
calibration at that point.
A convenient format for tabulating this data and
calculating the standard deviation is shown in figures
1 and 2.
7.0
UTILIZING THE DATA
See "An Improved Technique for Utilization of
Conformal Ballistics Sensor Calibration Data",
attached.
8.0
OPERATION
Apply pressure slowly, starting with the lowest
pressure working toward the highest, set the pressure
to specific values precisely and read corresponding
voltage output at each point. Do not dump pressure
at each point.
Due to the fact that a certain amount of pressure is
necessary to expand the cartridge case, a severe non-
linearity will be noticed at the low end of the
calibration curve.
A special technique has been developed to handle this
problem. Refer to the enclosed paper "An Improved
Technique for Utilization of Conformal Sensor
Calibration Data" for instructions in collecting and
using the conformal calibration data.
Also, read the operating guide supplied with the
sensor for further pertinent information regarding use
of the 090B Calibrator.
9.0
PRESSURE LIMITS
It is very important that maximum pressures are not
exceeded for the safety of operating personnel.
For pistol calibrators, and 22 rimfire, the maximum
pressure is 40,000 psi. For center fire rifle cartridges,
the maximum hydraulic pressure is 60,000 psi.
Do not exceed these pressures. The units were tested
at the factory only to the pressures stated here.
Exceeding these pressures may endanger personnel
operating this equipment.
