ProWeigh Filters for TSS

ProWeigh® Filters are 1.5µm Binderless Glass Fiber Filters with all preparation steps done for you.


ProWeigh® filters from Environmental Express are a time-saving, convenient and accurate way to perform Total Suspended Solids. By eliminating all the required filter preparation steps necessary for solids determination, the hands-on time required for performing TSS is reduced by half.

The 20th edition of Standard Methods, the definitive book of water and wastewater test methods, lists ProWeighs from Environmental Express by name. Method 2540C, Total Dissolved Solids Dried at 180°C; Method 2540D, Total Suspended Solids Dried at 103-105°C; and Method 2540E, Fixed and Volatile Solids Ignited at 550°C all specifically list ProWeighs as an acceptable filter. ProWeighs were approved for use by the Standard Methods committee in 1997. To use ProWeighs, simply remove one from its pan, place it on a filter funnel and filter your sample. After filtration is complete place the ProWeigh filter back in its pan and dry in an oven for the final weight determination. All the washing, drying and preweighing is done for you.

Download a brochure on the benefits of ProWeigh Filters

All ProWeigh filters are vacuum rinsed with three aliquots of deionized water. This step removes any loose fibers which could affect the filter's constant weight. The filters are then dried at 105°C in mechanical convection ovens, cooled and dessicated for 24 hours.

Filters are weighed on electronic analytical balance to the nearest 0.1mg. Balances are self-calibrating and are checked with in-house Class S weights. Our balances are also routinely certified by an outside party. A copy of the balance certification is included in each box of ProWeighs.

ProWeighs are supplied in individual aluminum pans labeled with the weight of the filter affixed with a Mylar® label. In addition to the filter weight, the label also displays an individual sample number. This information is also shown in a 128 bar code format. Our automatic labeling system prevents the transcription errors that can occur in the laboratory.

Download a cost calculation form to see if purchasing ProWeigh filters will save your lab money in addition to time and labor.

Complete data for each box of filters is available on our website! Product data includes:

  • Box ID Number
  • Filter ID Number
  • Both Filter Weights
  • Filter Material Lot Number

To access your data, simply go to our website, and type in your Box ID number (found on the product label on your box). The product data for all the filters in your box is populated on your computer screen.

Download your data into a CSV/Excel file with just one click. It's as simple as that. Your DoubleWeigh data will be stored in our system indefinitely. Access your data any time.

Click here for a Filter Balance Certification 2014 sheet.

Item No. Description
F934110MM ProWeigh Filters for TSS, 110mm, 100pk
F93432MM ProWeigh Filters for TSS, 32mm, 100pk
F93442MM ProWeigh Filters for TSS, 42mm, 100pk
F93447MM ProWeigh Filters for TSS, 47mm, 100pk
F93455MM ProWeigh Filters for TSS, 55mm, 100pk
F93470MM ProWeigh Filters for TSS, 70mm, 100pk
F93476MM ProWeigh Filters for TSS, 76mm, 100pk
F93490MM ProWeigh Filters for TSS, 90mm, 100pk
F96047PES Preweighed PES Filters, 47mm, 100pk


pore size? price?

The pore size on these filters is 1.5 microns. For pricing please login online or check with your sales representative.

I have a client who wanted to know the pore size of the F93442MM - ProWeigh Filters for TSS, 42mm, 100pk?

All ProWeigh filters are glass fiber, binder free, 1.5 micron pore size filters. They fit the specifications listed for TSS and TDS testing.

Is this Filter equivalent to Whatman 934-AH? Do you know what the AH stands for?

Yes - our glass fiber filters for TSS and TDS are equivalent to the Whatman Grade 934-AH.

F934110MM filter for TSS cost?

All of our pricing is available online by logging into your customer account. If you need help setting up or accessing your account please call our toll free number 1-800-343-5319 and speak with our customer support team.

What is the nominal pore size of your F93447MM - ProWeigh Filters for TSS, 47mm, 100pk? Thank you, Greg

This filter has a nominal pore size of 1.5 microns.

what is the micron size

This is a glass fiber 1.5 micron filter.

What is the min particle size that the F93490MM retains. Thanks. Elena.

These filters have a nominal pore size of 1.5um.

What is the pore size for this filter?

The nominal pore size is 1.5 um.

Is this EPA approved? Are the weights of the filters traceble to a NIST source? and do you supply supportive documentation?

The EPA typically does not approve pieces of equipment, but instead approves methods. For total suspended solids, SM2540 D 1997 is one of the more commonly used approved methods. There is a footnote in the section detailing the filter specifications that mentions Environmental Express ProWeigh by name as being acceptable for use. Each box of filters that you receive is accompanied by a certificate that gives balance ID’s and weight set reference numbers that are used to weigh the filters.

What would you recommend for zooplankton (copepods) Doubleweigh or Volitile?

If all you need is a preweighed filter, the ProWeigh would be your best option. A representative sample of these filters are double checked for proper weights instead of every filter as with DoubleWeigh. The volatile filters are only for use if the filter and the material on it are to be burned to remove volatile components. All of these filters have a pore size of 1.5 microns.

what is the grade of this filter?

This filter is a 1.5 um, binderless glass fiber filter. It is specific to the Total Suspended Solids analysis but does have other applications.

Why are ProWeigh filters 1.5 um when Standard Methods recommends 2.0 um or smaller?

All of the filters that are recommended by name in the footnote for Standard Methods 2540C have a listed pore size of 1.5 um. The size is slightly smaller than the maximum called for because every type of filter will allow some particles of a larger size to pass through. 1.5 um is a good size to get as close as possible without allowing too many large particles to pass through.

Do you provide the initial and confimation (final) weights of the TSS/VSS filters?

This documentation is not provided with the filters. The weight on the pan is the original weight of the filter and the secondary weight must be within +/- 0.0004g of the originial weight or the filter is rejected.

Can the pan ID# and filter weight be put in separate fields on an Excel spreadsheet if read with an imaging scanner?

Yes--this is possible. Customers have been successful in separating the two into different fields on an Excel spreadsheet or in their LIMS system.

Is both the filter number and tare wt included in the bar code information?

Yes--the bar code contains both the filter weight and the pan ID #.

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