Original ProWeigh Filters TSS/VSS

*Original ProWeigh Filters TSS/VSS

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

ProWeigh® Original filters from Environmental Express are a time-saving and accurate way to perform Total and Volatile Suspended Solids. Use of prepared filters significantly reduces hands-on preparation time in your lab. Listed in Standard Methods since 1997, our laser cut 1.5µm binderless glass fiber filters are prepared according to method. Filters are:

  • Washed 3 times in deionized water
  • Dried at 103 - 105°C (ProWeigh Double filters for Volatile Suspended Solids are then ignited at 550°C for 15 minutes)
  • Weighed to 0.1mg
  • Placed in aluminum weigh pan

Pans are labeled with weights in print and barcode formats. ProWeigh filters are approved for Method 2540C: Total Dissolved Solids, Method 2540D: Total Suspended Solids, and Method 2540E: Fixed and Volatile Solids. To use ProWeighs, simply remove a filter 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 final weight determination.

Filter Guide Link

As an added convenience, complete data for each box of 47mm ProWeigh Original filters is available on our website, http://www.envexp.com/filterdata. Just 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 an article about the benefits of using ProWeigh filters.

To determine time and cost savings in your lab by switching to ProWeigh, you can download our ProWeigh Cost Calculator.

Filter Balance Certification Sheet - Annual May 2015


Original ProWeigh Filters for TSS

Item No. Description
F934110MM ProWeigh Filters for TSS, 110mm, 100pk
F93425MM ProWeigh Filters for TSS, 25mm, 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

Original ProWeigh Filters for VSS

Item No. Description
F934110VOL ProWeigh Filters for Volatiles, 110mm, 100pk
F93425VOL ProWeigh Filters for Volatiles, 25mm, 100pk
F93442VOL Proweigh Filters for Volatiles, 42mm, 100pk
F93447VOL ProWeigh Filters for Volatiles, 47mm, 100pk
F93455VOL ProWeigh Filters for Volatiles, 55mm, 100pk
F93470VOL ProWeigh Filters for Volatiles, 70mm, 100pk
F93476VOL ProWeigh Filters for Volatiles, 76mm, 100pk
F93490VOL ProWeigh Filters for Volatiles, 90mm, 100pk


Will the pan keep its integrity in a muffle furnace at 550C?

These weigh pans are made of Aluminum and have a maximum operating temperature of 677°C. Our aluminum weigh pans handle the muffle furnace temperature of 550°C very well. However, the pan labels with the lot numbers and tare weights will burn off in the muffle furnace. I always recommend “writing” either the pre-weight or ID or both on the bottom of the pan with a pencil – you are actually making an indentation on the pan at that point. If you write with a Sharpie it also burns off but the indentation holds up well.

Does it matter what side of the filter (grid or smooth side) is placed down on the vacuum pump apparatus while filtering?

The “gridded” side of the filter should be placed down. The “wrinkled” side should be facing up.

What is the pore size of these filters?

These filters have a nominal pore size of 1.5 microns.

Should the filters be placed in desiccators once the package is opened?

These filters are ready-to-use right out of the box. They do not have to be stored in the dessicator.

Where do I find the certificate of analysis

The only certification available for all of our ProWeigh Filter products is the balance certification. This is available at the following link - http://www.envexp.com/download/techsupport/Certificates%20of%20Analysis/Balance%20Certification%20for%20Proweighs/Current%20Year/Balance%20Certification%202014.pdf

where do I find the certificate of analysis for a lot number

The only certification available for all of our ProWeigh Filter products is the balance certification. This is available at the following link - http://www.envexp.com/download/techsupport/Certificates%20of%20Analysis/Balance%20Certification%20for%20Proweighs/Current%20Year/Balance%20Certification%202014.pdf

is the direction of flow of solution important, if so from coarse side to smooth or smooth to coarse?

If you are following Standard Methods for the determination of various residues, i.e. TSS or TDS, you must have the coarse side up. This does slightly increase the effective filter area and allow for a larger total number of particulates to be collected. The actual pore size is not affected by direction of flow through the filter disc.

Could you please confirm the pore size of product F93425VOL? Is it 1.5 microns?

Yes the pore size is 1.5 microns. This is the same filter material that is used in our normal ProWeigh filters. It has had the added step of going through volatilization during the preparation procedure.

are the pans weighed?

The pans are not weighed. According to the method the pans should only be used as support when drying the filters in the oven. Only the filter and residue should be weighed.

how can I find the certificate of analysis on the proweigh filters

There is no certificate of analysis for the ProWeigh filters. There is a balance certification that is available. Go to http://www.envexp.com/coa and choose \"Balance Certification for Proweighs\" You will be able to download copies of our balance certifications there. We typically have the certification done in May.

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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