Brooks Instrument Blog

Yesterday I covered flow rate and reference conditions and talked about how important (or not) these are to specifying a variable area (VA) flow meter. Today, I’ll finish up my tips by reviewing fluid density and viscosity as well as accuracy.

Fluid: Density and viscosity
We always have questions about the fluid such as gas or liquid.  What are the density and viscosity?  Is it corrosive or opaque?  If it a know fluid such as air, nitrogen, water, etc.  The questions get much easier because the world has defined how these known fluids behave so we can easily determine density and viscosity for common fluids such as air, water, nitrogen, etc.  Which leads to the questions as to why do we need to know fluid density and viscosity?  Fluid density and viscosity are important because these two values allow us to select the right flow meter (meter size).  We call this sizing.  What is behind sizing?  Briefly, performance data has been collected on all of the different meters we offer.  We query the performance data and look for flow meters that fit the supplied process conditions (density and viscosity).  Usually there are many flow meters that fit your conditions.  From there it becomes a matter of preference, available options, price or accuracy.  This leads me to my last topic on VA meters, which is accuracy. Read more…

In yesterday’s blog post, I took you through why we need to know about your normal and maximum operating temperatures and pressures in your application to specify the right variable area (VA) flow meter for your process. Today, we’ll dive into flow rates and reference conditions.

3. Flow rate – minimum, maximum, normal
Of course flow rate is an obvious requirement but it is more complicated than it appears.  The goal is to specify a VA meter where the normal operating flow is in the 60% to 80% of the meter’s range.  Why you ask because a variable area meter is more accurate in the upper part of its range.  I will talk more about accuracy in my next blog post.  Of course a flow meter needs to be chosen that handles the minimum and maximum flows too.  The other component of flow rate is the units.  Read more…

Variable area (VA) flow meters will respond like the canary in the mine when the air quality changes.  If process conditions change there usually is an impact on flow rate.  For example if back pressure changes on gas flows the float/flow will change just as changes in liquid viscosity will have a similar impact to the float/flow.

VA meters reacting to changes in process conditions can be a good or bad thing based on a user’s viewpoint, which brings us back to the real question.  So why do we need so much information to specify the proper VA meter?  I will go through the questions and explain why it is necessary.  The information needed is: Read more…

I was just informed that as of yesterday, January 3, 2012, our long-time Brooks sales rep, Webco Controls, Inc, merged with Miller Energy Inc. This is pretty exciting news for our customers in the Northeast United States who deal with Webco. This merger will really enhance the technical inside sales support for customers as well as providing them a very broad range of instrumentation and valve manufacturers. Read more…

I have to say, this was a fun one to do around the holiday’s. I enjoyed seeing a lot of the guesses coming in for our Guess the Year this Flow Meter was Made blog post. A few thought the answer was in the serial number, but it wasn’t. For a while there I didn’t think anyone was going to get it right. So many people guessed within a  year! But the correct year was …

1954

We had 5 winners that will be receiving a 4GB memory stick in the shape of a Brooks GF40/80 Series mass flow controller/mass flow meter.

Happy New Year everyone!