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What is Grade 373?

Johnson Test Papers Grade 373 filter paper has high wet strength and a larger nominal particle retention rating than comparable Büchner filtration papers enabling fast filtering for gravimetric analysis of thick, coarse particles and gelatinous precipitates. It has a mild texture and high apparent density which favour good load capacity. Acid-treated with minimal fibre shredding, even when wet.

  • Large nominal pore size of 12-15 µm
  • Fast filtration speed (10 seconds according to DIN 53137)
  • High purity (0.015% ash maximum)
  • Compatible with Büchner funnel or Hirsch funnel applications

Johnson Test Papers offers three grades of low ash hardened filter paper for quantitative analysis. All three are designed for use in gravity and vacuum/suction filtration in Büchner and Hirsch funnel applications and can be customized for an exact fit.

Grade 373 filter paper can sustain fast vacuum or suction filtration in a Büchner or Hirsch funnel.
  • Fi.e. iron, aluminium, chromium and zirconium hydroxides
  • copper, copper sulfides, cobalt or iron
  • Si-determination in steel and pig iron analysis) in acid and alkali solutions.
  • Air and foodstuffs analysis .
  • Chloride and phosphorous in cement, coal and coke>

Whatman Cross Reference = No.54
Speed class Fast
Thickness (mm) 0.29
Pore size (μM) 12-16
Weight (g/m²) 80
Filtration Speed (sec*) 10
Burst Strength (Kg/cm²) >0.3
*According to DIN 53137
Available Sizes
Diameter (mm) Product Code
55 373055
70 373070
90 373090
110 373110
125 373125
150 373150
185 373185
240 373240
300 373300
320 373300