9-11-00 1) Mechanical Sensor outside dimensions: 1.1 by 1.3 by 2.3 inches. This includes the sensor body and all electronics. Estimated mass less than 100 grams. Sensor entrance aperature must have clear view of the ram direction. Acceptance is +-20 deg. 2) Power Requirements +28V battery pack (24V to 36V). Current draw of less than 30mA. 3) TM Requirements Total of 4 analog channels. 16-bit conversion. 0 to 5V range. DUST 2000 samp/sec LF 250 samp/sec SMON 250 samp/sec TEMP 125 samp/sec 4) Timing signals required SAMP -- A 2KHz 5V logic pulse with a known phase relationship to the A/D sample time for the DUST input. This clock is used to generate a 1KHz modulation in the dust flux. The phase of this modulation must be accurately aligned relative to the sample time. There are no particular requirements on the delay time but it must be known and remain constant (+-5usec) so that the dust detector can be set up properly. The default delay is SAMP rising edge 200usec (+-5usec) before the ADC convert for the DUST signal. Pulse width of about 20usec (not critical). SYNC -- A 5V logic pulse at the PCM frame rate. This pulse is used to lock the 1KHz modulation half cycle. It insures that odd and even numbered samples have a known relationship to the 1KHz modulation. DLEG -- A 5V logic level that is low on the upleg and +5V on the downleg. This is used to switch the detector from dust mode to ion RPA mode. Presumably this comes from a flight timer. 5) Interface connector SAMTEC FTSH series 20 pin ribbon cable connector. All returns are tied together and tied to chassis at the sensor end. pin signal description 1 SAMP 2KHz timing 2 RETURN 3 SYNC frame rate 4 RETURN 5 DLEG flight timer event 6 RETURN 7 LF low gain DC chan 8 RETURN 9 SMON ion sweep monitor 10 RETURN 11 RETURN 12 RETURN 13 DUST hi gain AC chan 14 RETURN 15 TEMP temperature sensor 16 RETURN 17 +28V power 18 RETURN 19 +28V power 20 RETURN