FILTER_TYPE_SIZE

 100  GLASS-FIBER FILTER (GF/F)
      101  Reeve Angel gf/f 984H       
      102  Whatman gf/f 24
      103  Whatman gf/f 47 mm
      104  Gelman gf/f 0.45u
      105  Gelman gf/f 0.8u 
      106  GF/C

 200  MILLIPORE 

 300  NUCLEOPORE
      301  Nucleopore >10 micron
      302  Nucleopore 2-10 micron
      303  Nucleopore <2 micron

 400  PAPER FILTER

 500  UNSPECIFIED FILTER-TYPE
      501  >10 micron (unspecified type)
      502  2-10 micron (unspecified type)
      503  <2 micron (unspecified type)

 900  COMBINATION FILTER-TYPES
      901  Whatman GF/C and HA Millipore