Cambridge Viscosity Blog

How to Choose a Viscometer

Apr 20, 2022 1:32:35 PM / by Patrick Riley


There are many different viscometer technologies and all have their merits, depending on the application. 

Before you go and talk to any manufacturers, it is important that you know your application specifications and you need to know what to ask so you don’t end up with an expensive paperweight. This guide will help you gather your information upfront so when you do reach out, we can assist you quickly and effectively.

Laboratory viscometers and process viscometers may have some technology and methodology overlap, but the conditions of use are different so we’re going to break this down into two separate groups.
Process Viscometers

What do I need to know about my application before I contact viscometer manufacturers?

  1. Line diameter
  2. Process communication connection (i.e. DIN, ANSI, threaded, etc.)
  3. Flow rate in the process (high and low)
  4. Particle sizes and particle size distribution in the fluid
  5. Solids concentration
  6. Temperature range of the process (high and low)
  7. Viscosity range of the product. If it is lab data, make sure you know the temperature at which it was measured, otherwise your range will be way off.
  8. Line pressure
  9. Is your fluid viscosity Newtonian or non-Newtonian
  10. What is the pH
  11. Do you know the chemical compatibility (e.g. do you need 316L SS or Hastelloy?)
  12. How often do you change products or shut down the process?
  13. Is there a need for cleaning between runs?
  14. What are your required outputs (e.g. display, analog, Modbus, Profibus, etc.)?
  15. What power source is available in the installation area?
  16. What is the area NEC classification?

Laboratory Viscometers

Lab viscometers have some differences from the process, but here is a breakdown of what you’ll need to know about your lab before reaching out to viscometer manufacturers:

  1. What is the available sample volume per test?
  2. Are any solvents used? What are they?
  3. Number of tests per day?
  4. Do I need to follow a specific standardized method or protocol during the measurement (e.g. ASTM Dxxx or CFR-xxx)
  5. Is the fluid viscosity Newtonian or non-Newtonian?
  6. Do I need controlled shear-rates?
  7. What are the required test temperatures?
  8. Do I already have a re-circulating temperature control bath? Is one required?
  9. What is the viscosity range of the samples?
  10. Are measurements at non-ambient pressures required? How high or low?
  11. What is the available bench space?

Once you’ve collected that data, you’ll be able to get specs from the manufacturer and see what’s a match. That said,  not all conditions or specification can be met. There are some questions that you should be asking, even if everything looks like a match:

  1. Will this device reliably measure my fluid?
  2. Is it sensitive to particles?
  3. What is the accuracy and repeatability in my measurement range?
  4. Is it sensitive to flow?
  5. Will my fluid deposit or coat the device and cause the readings to drift?
  6. What is the suggested calibration interval?
  7. Can we re-calibrate it ourselves?
  8. How much does a calibration cost? Are Service contracts available?
  9. How long is the lead time for Service?
  10. Can the cleaning procedure easily be explained?
  11. Have you provided viscometers for this application before?
  12. Have you sold to my company before?
  13. What is your return policy?
  14. What are the consumables?
  15. What is the cost for the necessary consumables per year?
  16. Can I get that in writing?

There is a viscometer out there for everyone, so check with a few different places. You can put a viscometer model number into to see what their usage in academic circles. You can also type “reviews” into a search engine to see if there have been wide-spread complaints.

Well, we hope you find this guide helpful. If you have any questions, don't hesitate to reach out to one of our application engineers. 


Have a Question or Comment? Send us a Message. 

Tags: process viscometers, lab viscometer, in-line viscometers

Patrick Riley

Written by Patrick Riley

Vice President of Process Analytics

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