TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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(2) Specific application to part No. 10865297 cylinder (thick wall cylinder with groove in periphery of mounting flange). The reflectoscope, search unit fixture, and master checking cylinder combination provides a specific functional detection method. The pulser of the reflectoscope transmits short bursts, or pulses, of electrical energy through a cable to the search unit fixture at which point these pulses are routed to the piezoelectric probe. The probe changes the electrical pulses into ultrasonic energy and transmits them through the trans- mitting medium (water) into and through the cylinder barrel wall, toward the outside diameter of the aluminum muff or crack, and back by the same route to the probe. The probe then changes the ultrasonic energy into electrical pulses which are transmitted by cable back to the reflec- toscope where a characteristic wave form is displayed in the screen. Additionally, the reflectoscope embodies an alarm system which may be set to a specific level, to signal when the crack or flaw is detected in the cylinder. d. Detailer Calibration of the Cylinder Barrel Tester. (1) General. The following adjustments apply to a new tester. Once these adjustments have been made, they will seldom require readjustment under normal conditions. Should the inspection procedure reveal an abnormally high cylinder reject rate, the tester adjustments should be checked to be certain the readings are correct. However, it is good practice to check all adjustments periodically to insure against ac- cidental tampering. The reflectoscope cover and search fixture probe protector should be in place whenever the tester is not in use. Note. The cylinder barrel tester should not be operated in close proximity to electrical appliances, or false alarming may result. (2) Establish the wave form on the reflectoscope display screen and set the alarm. (a) Remove the cover from the reflec- toscope. (b) Plug the reflectoscope into a 115 volt 10 volt, 50 / 60 cycle single phase power source. Turn the POWER (SCALE ILLUM) knob clockwise and allow time for warm-up (approximately 10-15 minutes). (c) Adjust the sweep delay (upper left hand control panel). (1) Turn the SWEEP DELAY knob (red) clockwise to “1”. (2) Adjust the SWEEP DELAY knob (inner black) to adjust the initial pulse wave over the left hand vertical division marker on the display screen. (3) Place the SWEEP toggle switch to “PRESET". (4) Place the left hand INCH- ES / DIV lever to “2”, and, place the right hand lever to “1”. (5) Turn the MARKERS knob (red) counterclockwise to “OFF”. (6) Turn theALT. DISPLAY SHIFT VERT screw fully counterclockwise. (d) Pulser / receiver unit adjustment. (1) Place the TEST switch to “NORMAL”. (2) Turn the FREQUENCY knob to “5.0”. (3) Place the SENSITIVITY switch to “X1“ and turn the SENSITIVITY control knob to “1”. (4) Turn the REJECT knob coun- terclockwise to “OFF”. (5) Turn the PULSE LENGTH knob so that the dot is at the “12:00 o’clock” position. (e) Display screen adjustment. (1) Turn the POWER (SCALE ILLUM) knob counterclockwise, but not “OFF”. (2) Place the GATE OFF switch to “GATE OFF”. (3) Adjust the VERT screw to place the horizontal wave form line on the zero horizontal scale line (view A, fig. 53). 6-61