Total Nitrogen by Combustion

LECO FP528 Nitrogen Combustion Analyzer

Start Up

  1. Wash hands.
  2. Move carousel so that position 1 is one space right of arrow.
  3. Delete previous results; select row 1 in gray – scroll through final record – right click – delete.
  4. Run leak checks.


  1. Highlight first block under Name – Click Samples, then Blank – enter 1 for number of blanks –  OK  
  2. Type in 1 for the beginning location number to the left of the first blank – press enter.  
  3. Click F5 – analyze  (If not ready – click OK, then click F5 again).  
  4. Run 9 more blanks.  Click Samples, then Blank - enter 9 for number of blanks - click OK.
  5. Click F5 - analyze (If not ready - click OK. then click F5 again). 
  6. Look at the last two blanks.  If not consistent and low (>0.01), add another blank to analyze and repeat until at least two values are consistent and low.
  7. When at least two values are consistent and low, highlight the rows you want to use to set the blank on (in gray).  Check the STD (lower right) to make sure STD <0.01% for the two highlighted blanks.
  8. Click configuration - blanks - OK.


  1. Highlight open space under last blank name – Type EDTA – place foil on balance with tweezers – tare balance – weigh 0.20__ g EDTA – press print button on balance to transfer weight to screen.  (Keep balance pan clean while weighing.)  
  2. Carefully wrap foil and place in proper location on carousel.   (If you feel any EDTA on your fingers when wrapping the sample, the bag is broken - so discard.)
  3. Press down arrow on keyboard to proceed with next EDTA sample.  
  4. Weigh 3 EDTA samples - click F5 to analyze.  Wait until analysis is complete on all three samples. 
  5. If all three values are consistent and close to 9.56, highlight 3 EDTA samples (in gray).  STD in lower right should be <0.035.
  6. Click configuration – then calibrations. – Click Ok – Ok (factor in equation should be > 0.8.  Recalibrated EDTA values should be close to 9.56).


  1. Highlight name box under last EDTA.  
  2. Type in peach – weigh – enter weight from balance as above.  Wrap sample foils and position as above.   (Peach should be 2.88 +-0.06.  If not in this range the unit will stop.  You may need to run some more blanks and recalibrate.)
  3. Proceed with samples – weigh ~0.1 g (maybe more or less depending on fluffiness). – Weigh at least 3 samples before starting to analyze so you can stay ahead.  
  4. Keep balance pan clean while weighing.
  5. Solid manure samples must be weighed in the back.  The sample numbers and weights may be entered by typing in on the computer.

Print Report 

  1. To print report – highlight 1 – end sample (in gray) – click file - print – OK – OK
  2. Check data for accuracy (peach should be 2.88 -+ 0.06) – Record values and do rechecks if necessary.

Clean Up 

  1. Clean up workstation.
  2. Check tubes for maintenance.
  3. Click F10 OFF.

If the power is out for an extended period of time and the furnace cools down, it must be powered up for at least 1 h before using.  Combustion furnace temp can be checked by clicking on Diagnostics - Ambients.  Temp should be 825 - 875 C.

If the sliding head is not sliding to drop the samples - Click Diagnostics - Solenoids.  Click 4th box down (Block Seal).  Click 1st box (Block open).  You should hear and see the block open.  Unclick both boxes.  Close.