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    What is Grade 353?

    Johnson Test Papers’ Grade 353 filters support inorganic analysis and other forms of instrumental analysis. The low ash content also makes Grade 353 appropriate for gravimetric analysis requiring sample combustion.

    • Very low ash content (0.007% ash concentration maximum)
    • Intermediate pore size of 8 - 12 µm
    • Filtration speed of 20 second according to DIN 53137
    • Particle collection between that of Grades 352 and 354

    Johnson Test Papers offers other ashless grades to ensure that you have the appropriate particle retention rating for your needs. Hardened ashless grades are also available for analysis that use strong acid/alkali solutions.

    Particle collection and inorganic analysis

    Johnson Test Papers’ Grade 353 can be ashed during gravimetric analysis without contributing substantially to the measured weight. These medium-fast filters are appropriate for:
    • Inorganic analysis in the construction, mining, and steel industries for coarser precipitates such as lead, iron and silver sulphide, alkali carbonates, lead chromate, arsenic, antimony and cadmium
    • Particle collection for air pollution monitoring for subsequent analysis by X-Ray fluorescence (XRF) techniques
    • Soil analysis
    • Foodstuffs filtration analysis

    Whatman Cross Reference = No.43
    Speed class Medium fast filtering
    Thickness (mm) 0.16
    Pore size (μM) 5-8
    Weight (g/m²) 84
    Filtration Speed (sec*) 50
    Burst Strength (Kg/cm²) < 0.20
    *According to DIN 53137
    Diameter (mm) Product Code
    mm: 55 Product code: 353055
    mm: 70 Product code: 353070
    mm: 90 Product code: 353090
    mm: 110 Product code: 353110
    mm: 125 Product code: 353125
    mm: 150 Product code: 353150
    mm: 185 Product code: 353185
    mm: 240 Product code: 353240
    mm: 300 Product code: 353300
    mm: 320 Product code: 353320