The System 83 measures chamber pressure using a 0 - 10 volt signal from an external transducer and charge amplifier. This signal is digitized (10 bit accuracy) at 18 microsecond intervals. The pressure curve is displayed on the computer screen immediately after a shot is fired, and digital readings are provided for peak pressure, area under pressure-time curve, and rise-time. The displayed pressure curve can be chosen to be either 2 or 4 milliseconds in dura-tion. Curves are stored for subsequent printout.
Alternatively, the System 83 can measure chamber pressure using a small strain gage glued over the chamber area of a barrel. The dimensions of the barrel and the assumed material characteristics provide the scale for the pressure measurements.
The system uses either two or three Model 57 Infrared Photoelectric Screens located near the muzzle. If used, the third screen is located at the midpoint between the other two. The system displays instrumental velocity between the two primary screens. The proof channel displays the difference in velocity measure between first and middle screens referenced to the velocity measured between first and last screens.
The system can handle three additional Model 57 Infrared Photoelectric Screens downrange to measure terminal velocity, time-of-flight, and ballistic coefficient. The 8355 downrange adapter is required to use the additional M-57 screens downrange.
MODEL 57 INFRARED PHOTOELECTRIC SCREENS
The Model 57 Screens function with all projectiles larger than .17 caliber and faster than 300 fps. Infrared diodes are used for the light source. They have the same outside dimensions as the older Model 55 screens. More detectors allow better coverage of the shooting window. The output pulse is +12 volts of approximately 2 milliseconds duration. For additional information refer to our Model 57 web page."
The ACOUSTIC TARGET may be used for bullets with a remaining velocity of greater than 1500 fps at the target. Four acoustic sensors record the passage of the bullet's Mach cone. The system displays the exact hit location on the target, time-of-flight, ballistic coefficient, and estimated velocity at the target.
The System 83 measures the rate-of-fire and the velocity of individual rounds in burst fire. It can capture the data from each round of a 30-round burst, at up to 2,000 shots-per-minute.
The metal case is 17" wide x 8" deep x 1.75" high, and can be fitted with ears for mounting in a standard 19" rack. The System 83 must be connected to a Windows® computer via an RS-232 serial port.
The computer furnished by the user must be capable of running Windows® 95 or later operating system. The computer must have a serial port to connect to the Model 83. If the computer has no built-in serial port, the user must provide a converter that adapts an USB port to RS-232.
Model 83 32-bit software for Windows® 95, Windows® 98, Windows® ME or Windows® NT, Windows® 2000, and Windows® XP is now available. Evaluation versions can be obtained from Oehler Research for current Model 83 owners. The Windows® version of the Model 83's program adds some of the most asked for features while retaining the general functionality of the Model 83 DOS program.
The Windows features include:
The sample output page shows the complete test results. A complete record of the test conditions is shown in the left column of the upper block. Complete gun and transducer information is shown in the center column. Complete load information is shown in the right column. All individual results (velocities, time-of-flight to target, ballistic coefficient, pressure data and pressure curve) are shown for each shot. A summary block includes the statistical summary of each parameter, and a target plot shows the recorded group along with group measurements. The summary is followed by a condensed standard-atmosphere ballistic table computed from the measured velocities and ballistic coefficients.
Oehler Research, Inc.
P.O. Box 9135
Austin, Texas 78766
(512) 327-6900 | FAX (512) 327-6903
Toll Free (800) 531-5125