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Problem Resolution Model 1130 & Model 1135

Problem Resolution Model 1130 & Model 1135 . Frank Schaedlich. 330 Nantucket Blvd. Toronto, Canada M1P 2P4. Rev 1.12 Aug 2004. Classes of Problems. System leaks System contamination Excessive restriction Mechanical failures Analytical problems. System Leaks. Why are my blanks so high ?.

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Problem Resolution Model 1130 & Model 1135

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  1. Problem ResolutionModel 1130 & Model 1135 Frank Schaedlich 330 Nantucket Blvd. Toronto, Canada M1P 2P4 Rev 1.12 Aug 2004

  2. Classes of Problems • System leaks • System contamination • Excessive restriction • Mechanical failures • Analytical problems

  3. System Leaks Why are my blanks so high ?

  4. Leak Points

  5. Impactor Fittings Difficult to detect Will primarily affect the amount of particulate being detected Coupler: 1130-35 Will give higher Hg0 numbers during sampling May also give bad zeros during desorb phase Also applies to 1130 only systems (elbow) Leak Points

  6. RPF Tail Fitting Common source of leaks Must tighten securely Can use a layer of Teflon tape RPF units can each be different Sample Filter - DM Common source of leaks Takes practice to tighten up housing properly Ensure membrane is not creased Leak Points

  7. Junction Tee Big leak here can actually result in higher area counts during zeros than during sampling! During sampling, Tee is filled with outside air (PM ON) During zero, we have indoor air at Tee (PM OFF) Sodalime Trap Check all four seal points! Trap uses standard Quikgrip® fittings Leak Points

  8. Filter Holder – Model 2537A Even more critical than usual because of low pressure at this point Internal 2537A leak If leak is in valve assembly, may result in bi-modal areas Leak Points

  9. Restriction Points Why are my pump(s) racing?

  10. Notes on Restriction • Every bit of restriction within the system is cumulative • Effect is non-linear • System will operate fine, with pumps loafing along • When the threshold is exceeded, one or both pumps will suddenly start racing as they attempt to meet their target flows

  11. RestrictionPoints

  12. Impactor Becomes very restrictive if elutriator is screwed in too tightly Keep impactor disk clean RPF Pack quartz wool loosely Do not use too much wool Repack filter more often under high particulate loadings Restriction Points

  13. Pyrolyzer Use only minimum quartz wool required to keep pyro fill chips in place May use coarser fill quartz chips Sample Filter - DM Make certain that you use a 1 µm glass membrane Not 0.2 µm Teflon! Restriction Points

  14. Sodalime Trap Use coarse S/L crystals (8 mesh) Use minimum quartz/glass wool for packing ends Pack all material loosely Model 2537A Filter Remember to change membrane often Model 2537A itself may become restrictive V2 or V3 Cartridges Restriction Points

  15. 1130 Can’t Maintain Flow • Sample path restriction • BPR set too high • V2 is restrictive

  16. 2537A Can’t Maintain Flow PM can maintain flow but 2537A pump can’t • Excessive upstream (1130 & 1135) restriction • There is such a high vacuum present at the Tee junction that 2537A can’t pump full flow against it • Reduce 2537A flow • Increase PM flow • Remember to change factors! • 2537A has become internally restrictive

  17. Impactor Cut Size vs. Flow • Impactor cut size is dependent on actual volumetric flow at current temp & pressure • Model 1130 and 2537A regulate flow based on liters/min at 760 mmHg, 0 °C • Good reason to lower pumping rate at high altitudes

  18. Impactor Cut Size vs. Flow

  19. Common Contamination Points

  20. Contamination Points ??

  21. Impactor inlet Various Symptoms Dirty impactor surfaces may: Add or remove Hg0 or RGM May not result in high zero areas Coupler: 1130-35 Very high readings on 3rd denuder heat cycle Material may degas a lot of Hg when it gets hot Clean with methanol Vacuum oven Also applies to 1130 only systems (union & elbow) Contamination Points

  22. RPF Low Hg0 readings Dirty RPF may scrub out elemental Hg when sampling High zeros during desorb Pyrolyzer High blanks Ensure that only minimal quartz wool is used Should not extend into tail area Tail isn’t heated hot enough to ensure self cleaning Contamination Points

  23. ¼” Coupling tubing High Blanks May receive deposits Particularly noticeable with Model 1130 only Volatilized KCl Heated Line High Blanks & ?? Heated line may scavenge Hg0 May be responsible for cartridge “skunking” effect in some cases Clean line as part of normal maintenance cycle Contamination Points

  24. Sodalime High Blanks Change often with fresh soda lime Do not buy large containers of the soda lime Always keep tightly sealed in dry area May also scavenge Hg Preferably heated above the dew point of sample air 2537A Filter High Blanks Sample filter should be replaced as part of normal maintenance cycle Contamination Points

  25. Contamination Points Water in Canisters High Blanks • Problems can occur if canisters become waterlogged. (TN-311) Only occurs if: • Warm humid air outdoors • Air conditioning indoors • Condensation can actually cause corrosion of canisters! • Probably responsible for passivation after desorb cycle • Use driest ambient air available • Use air dryer if required

  26. Mechanical Problems

  27. Pump Hunts during Desorb • Not a problem as long as zero air keeps flowing to impactor • Increase Zero flow setpoint • Increase BPR setting

  28. Oven is Slow to Heat • Oven exhaust vent flapper is open • Ensure that flaps are free swinging and are operating properly • Ensure that 1130/35 are mounted perfectly upright! • Low line voltage • Get CVT (at least 1.5 kVA rating!) for 1130 or 1135 • Defective heater • Check & replace

  29. GFI Trips - A • Moisture inside of case • Check & replace door seal • Check top access door of 1135 • Ensure mounting board is absolutely flat (Warped board may twist case) • Ensure door locks seal properly • If blowing rain or snow is being sucked in, you may need to cover case inlet vent

  30. GFI Trips - B • Heater may be shorting • Usually only a problem with earlier generation heaters • T/C may be shorting to heating coils • Heating coils may be shorting to ground • Replace heater

  31. Freezing of Zero Air Line • The only available solution here is to use dry outside air as zero air source • Even if the internal line was moved, insulated, etc., the air would frost up somewhere inside external zero air components • Must purge zero canisters of moisture when moving them from temperate to arctic conditions

  32. Analytical Problems

  33. Cartridges Skunked after Desorb - A • Ensure sufficient line voltage to analyzer (> 115 VAC/230 VAC) • Check voltage to analyzer during heating • Use Voltage stabilizer or high quality / capacity UPS • Check heater screws (8) for tightness

  34. Cartridges Skunked after Desorb - B • Add sodalime trap (TN-304) • Wet or corroded zero air canisters (TN-311) • Replace canister(s) periodically • Install 1130 plumbing fix (TN-313) • Purge with dry gas to dry interior fill material • Use driest available ambient air source • Use gas drier (being evaluated by Tekran Aug, 2004) • Add Tenax trap (TN-310)

  35. Sodalime problems • Replace soda lime • May have batch that has gone bad

  36. Summary • These are the most common problems that have been experienced with the 1130/35 under field conditions • Appear to be resolvable in most cases

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