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    What is Grade 352?

    Grade 352 high purity filters from Johnson Test Papers are general-purpose papers for quantitative analysis. This grade has medium flow rate and good particle retention and is the most commonly used acid-washed filter. High-purity filters support accurate analysis in applications sensitive to very low levels of background contamination and in gravimetric analysis where ash content might affect weight measurements of combusted samples.

    Johnson Test Papers offers a range of ashless filter paper for your gravimetric analysis needs. See our other ashless grades to find the right filter for your sample, or use our hardened ashless grades if your analysis involves strong acid/alkali suspensions.

    Grade 352 covers a wide range of general ashless analytical filtration applications.
    • It is used for gravimetric analysis of various components (e.g. cements, copper, clay, bismuth, silicon, iron) found in heavy industries such as construction, mining or steel.
    • It is also used for filtering sludges, determination of oils in water and determination of sediments in milk.
    • Grade 352 is also used as a high purity filter containing 0.007% maximum ash content for speedy filtering of trace elements such as silver chromate, lead sulfate, coarser precipitates of calcium oxolate, zinc and ammonium hydroxide.
    • Grade 352 is also found in general soil analysis for separating solids from aqueous extracts.
    • Used as a clean-up filter for solutions prior to atomic absorption (AA) spectrometry Being a very pure filter, it can be used to capture radionuclides and traces of elements from the atmosphere.

    Whatman Cross Reference = No.40
    Speed class Medium Filtering
    Thickness (mm) 0.15
    Pore size (μM) 3-5
    Weight (g/m²) 84
    Filtration Speed (sec*) 100
    Burst Strength (Kg/cm²) > 0.20
    *According to DIN 53137
    Diameter (mm) Product Code
    mm: 55 Product code: 352055
    mm: 70 Product code: 352070
    mm: 90 Product code: 352090
    mm: 110 Product code: 352110
    mm: 125 Product code: 352125
    mm: 150 Product code: 352150
    mm: 185 Product code: 352185
    mm: 240 Product code: 352240
    mm: 300 Product code: 352300
    mm: 320 Product code: 342320