500C Advanced Training Outline

Transcription

1 500C Advanced Training Outline 1. Opacity Basics 2. Math used with the 500C 3. Trasmissometer Evolution Single Pass 1. Simple 2. Ambient light interference 3. Difficult to verify calibration Double Pass Beam Splitters 1. Retro 2. Easier to Calibrate 3. Ambient light interference 4. Non-linear output Lamp Modulation Mechanical 1. Mechanical modulation 2. Chopper wheel 3. Stable Motor 4. Moving parts Lamp Modulation Electronic 1. LED 2. Rugged 3. Longer life 4. Spectral Response C Optical Path Led aperture assembly Reference Detector 1. Feed back loop 2. Stable LED intensity First surface mirror beam splitter Projection lens 1. Factory adjusted 2. Focus beam on retro at calibration distance Exit Window Cal Wheel 1. Not a chopper wheel 2. Used for calibration checks 3. Rotates continuously 4. No glass in open section to read stack opacity Retro-Reflector beam splitter Signal detector Eye piece

2 5. Stack Equipment Calibration distance Purge system 6. Optical Head Board Block Diagram 1. Power supply on board Test Points ± 0.5VDC, < 5mVAC Signal and frame ground separate 2. Square wave generator 100hz ( ) or 45hz( ) 3. Digital oscillator- 2.5Khz carrier 4. R72 voltage (< 2VDC rev P and ) or (5.4VDC pre rev P) Set by R3 and pot R7 5. 0% opacity = -7.5VDC ± 1VDC Set by R % opacity = 0.0mA output; 0% opacity = 20.0mA output Adjust R33 for 0.0VDC at 100% opacity Adjust R40 for 0.0mA 100% opacity Adjust R45 for 20.0mA 0% opacity 7. Cal Kit Unit specific Used to create 0% and 100% opacity on stack Explain Iris and R49 adjustment (off stack only) 7. Retroreflector Passive device Diamond scotchlite or corner cube (pathlength dependent) Purge Shutter (optional) 8. Overfill vs Underfill Spot size determined by led aperture Misalignment 9. Calibration Wheel Rotates at 60RPM (50 Min. to 70 Max.) Belt driven from 110VAC motor Continuous cal checks Continuous stack reads Zero and Span reevaluated every 6 minutes Stack evaluted once a second Turn wheel off any time optical head hinge is open Zero cal used for dirt determination 1. Zero corrected to read zero 2. Zero drift shown as dirt 3. Dirt can be positive (real dirt) or negative (electronic drift) 4. Dirt above 4% or below -4% will cause alarm Object Sensors 1. IR source and dectectors 2. Reflective tape 3. Position adjustment sensitive 4. CR1 & CR2 in J-box

3 10. Purge Wiring Sail switches Produces a 3 state voltage +15 VDC = good purge -15VDC = purge fail 0VDC = stack power fail 11. Junction Box Input power Measurements for object sensor adjustments S1 power switch for head and cal wheel S2 three contact switch 1. S2A bypasses opacity meter will wheel is running 2. S2B places a 10,000 ufd cap across load to head while wheel is off 3. S2C turns cal wheel motor on/off TP1 - TP2 used to measure output current from optical head (10 ohm resistor) VDC = 100% opacity VDC = 0% opacity 3. Preferred measurement point to make current driver adjustments to optical head 4. Calculate filter values in cal kit testjacks OP = S3 set button (SETS) 1. Used to calibrate the remote panel Two step process Stack Set (Cal kit installed with no filters, 20mA output from head) 1. Press and hold S3 for 10 seconds, leave monitor undisturbed for 6 minutes 2. Establishes full scale (0% opacity) reference for opacity calculations in remote Cal Set (Optical closed and wheel running) 1. Press and hold S3 for 10 seconds, leave monitor undisturbed for 12 minutes) 2. Establishes reference values for Cal zero and Cal Span 3. Resets dirt correction to 0% 2. Perform Sets any time electronic adjustments are made to the optical head 12. Remote Display Visual displays, 4 relays, and 4 analog outputs Opacity and calibration calculations Stack taper correction Three Circuit Boards 1. Power Supply DC voltages for panel operation 11VAC for clock operation +15VDC & -15VDC ± 0.5VDC, < 5mVAC tolerance 24VDC relay supply 130VDC not used on opacity monitor 2. Microprocessor Brain All Calculations EPROMs IC5, IC7, IC8

4 Ram IC6 battery backed up Two serial ports (typically not used but available) Configuration stored in EPROM IC7 or RAM IC6 1. IC5 Sum Check = D586 : configuration burned into EPROM IC7 2. IC5 Sum Check = D3D9 : configuration stored in RAM IC6 Section L in manual for configuration variables Serial Ports used to re-configure Save hard copy of configuration variables 3. Remote Display Board Input - Output Receives all data signals from stack Converts all data from stack to digital and passes it over to micro Receives all digital answers from micro and converts it to displayable form IC16 1. Display driver 2. Converts digital data from micro and drives all lights on panel except POWER IC21 1. Reads all switches except POWER 2. Reads jumper position of JU9 (normally out -- only used to set clock -> discuss later) 3. Note S6 can be controlled by dry contacts on back of panel IC5 D/A converter 1. R43 & R44 adjustments 2. Current driver Adjustments Relay K4 is failsafe normally energized Analog input Channel #0 used for current loop from head 1. Check IC31 after lightning induced failures, can be replaced with IC23 Optical Isolators 1. IC26 & IC27 read purge power status from stack 2. IC28 & IC29 read cal wheel position data 3. IC30 reads Set Button from J-Box 13. Stack Taper Ratio Texit = Tmonitor^str Filters read in j-box are not corrected for taper Readings on remote panel are corrected for taper 14. Remote Buttons Mode Switch and optional forced cal Lamp Test and changing set points Setting Clock (JU9) Using S1 & S2 to check Full, Low, and Mid Scale 1. Bypassing while viewing data 15. Accumulators Cal Wheel RPM Dirt calculations Span Drift calculations Instantaneous calculations Raw readings not corrected for taper ratio

5 16. System Status Word 17. Laptop Communications (if applicable) Null modem cable Procomm or other com. package Set Variables Output configuration Analog Output Selection Options Relay configuration Reading variables Changing variables Logging variables 18. Fibrelink (if applicable) Signal description 19. Maintenance Check Sheets Explain steps Reading Stack Taper Ratio from Remote Optical Alignment Optical Head Test Points Review Filter Checks with Cal Kit Review Stack Taper Ratio implications on filter checks 20. Hands On & Test