TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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(j) Turn the SYNC switch (on transigate) to MAIN PULSE, and the GATE OFF switch on. (k) Turn the START knob (on trans- igate) to “2”. Adjust the START VERNIER knob so that a downward jog is in line with the 7th from the left vertical scale line on the display screen. Place the search fixture UPPER- LOWER switch to “UPPER”. (l) Turn the LENGTH knob (on trans- igate) to “1“. Adjust the LENGTH VERNIER knob to end the gate at the right hand edge of the flaw signal (approximately 9-1 / 2 vertical scale lines from the left of display screen). (m) Adjust the VERT screw to place the lower gate line over the zero horizontal scale line on display screen. (n) Adjust the FOCUS and ASTIG knobs for the sharpest wave form. (0) Adjust the SENSITIVITY control knob (Pulser / receiver unit) until the echo pulse measures 2-1 / 2 inches high on the display screen (view D, fig. 6-53). (p) Turn the REJECT knob (pulser / receiver unit) clockwise to the reduce the echo pulse height to 1 inch (view E, fig. 6- 53). (q) Turn the ALARM LEVEL knob (on transigate) to + AUTO RESET. Rotate the ALARM LEVEL vernier knob clockwise, then counterclockwise until the light just appears on RESET button. Place the AUDIO switch to “ON” and the alarm will sound (buzz). (r) Turn the REJECT knob (on pulser / receiver unit) counterclockwise to “OFF”. The echo pulse height will then return to 2-1 / 2 inches (view D, fig. 6-53). ( S ) Continue clockwise rotation of the search until handle until a heavy echo reflection enters the gate (view F, fig. 6-53). The heavy reflection indicates that the search fixture probe has reached the maximum downward travel. The cylinder barrel tester is now adjusted to establish the wave form. (t) Turn the POWER KNOB to “OFF”. Disconnect cable and remove the search fixture from the master checking gage. Install probe protector and reflectoscope cover. Pour water from checking gage. e. Establish the Wave From on the Reflec-. toscope Display Screen for Daily Operation. (1) Preliminary calitiration. (a) Remove the reflectoscope cover. (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. (c) Turn the POWER (SCALE ILLUM) knob counterclockwise, but not to “OFF”. (d) Turn the SENSITIVITY control knob to “l”, and the REJECT knob to “OFF”. (e) The wave form on the display screen should be similar to view G, fig. 6-53. Note. Should the wave form not appear, or is markedly different than that shown in view G, figure 6-53, recalibrate the tester in ac- cordance with the instructions in paragraph d, above. (f) Pour water into the master checking gage to the “FILL” level (five inches from top), refer to paragraph d (3) (a). Place the marked defect portion of the gage facing the operator. Note. Wipe all air bubbles from the cylinder wall. Bubbles may cause a false alarm signal. (g) Remove the protector from the search fixture probe. Place the search fixture in the master checking gage with the fixture flange resting on the cylinder mounting flange. Move the probe to the top of its travel and place the fixture UPPER-LOWER switch to “UPPER”. (h) Connect the cable to the search fixture and the reflectoscope at connector “R”. The wave form on the display screen will be similar to view H, fig. 6-53. (i) Rotate the search fixture handle clock- wise to move the probe downward. Rotate the search fixture handle until the echo pulse, or spike (view D, fig. 6-53) is shown on the display screen when the fixture pointer alines with the defect on the master checking gage. (j) Rotate the search fixture handle to move probe slightly upward and downward until a maximum pulse is seen on the display screen. (k) Adjust the SENSITIVITY control knob to probe an echo pulse height of 2-1 / 2 inches (view I, fig. 6-53). (l) Turn the REJECT knob clockwise to reduce the echo pulse height to 1 inch. (m) Turn the ALARM LEVEL knob (on transigate) to + AUTO RESET. Rotate the ALARM LEVEL vernier knob until the light just appears on RESET button. The alarm will sound (buzz) when the AUDIO switch is “ON”. 6-64