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Totalizer Averaging Smooths Out the Data in Flow Measurements

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Alicat’s optional totalizer feature is a great way to meter the total flow through a system. Adding a totalizer to a controller means you can dispense fluids in set quantities. We call it batch mode: set a total mass desired, set a flow rate, and the controller stops when the delivery amount is reached.

Totalizer averaging adds another number to your totalizer screen—the average flow rate during the metered period.  Calculating the average after the sample has finished is simple, but real time averaging can be tedious and require additional programming.  Why not just have it on the screen?  Not only does totalizer averaging appear in the screen, it also appears in the serial data stream—right next to the totalizer value. Now you can easily streamline your existing communication programs.

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Totalizer averaging can be extremely helpful during leak checking or flow characterization.  Using a mass flow device to control the pressure on a device under test and while measuring the flow rate is a compact solution essentially including two devices in one.  For smaller flow rates and volumes, minute changes in pressure will force changes in flow rates—which in turn change the pressure.  This can lead to an oscillation of both pressure and flow rate.  While the oscillation is natural, it can make it difficult to determine a single number to report.  With totalizer averaging, the average flow rate can easily be seen and recorded in real time rather than waiting until the process is complete to calculate.

Alicat devices have always had a flow averaging feature available to help minimize noise, since we sample in milliseconds. For users who are unaccustomed to a fast-responding sensor, the totalizer averaging can be easier to read, and helps to correlate our flow measurements to results from slower-responding instruments.  Totalizer averaging gives the ability to average flow measurement data over variable periods—from milliseconds to hours—extending the possibilities.

If the totalizer software is already on your device, the totalizer averaging feature can be added easily in the field via serial communication.  For those who are familiar with serial communication, simply add 1024 to the current number in register 88.  (Need a little help getting set up for serial communication?  Our applications engineers can help you out). The totalizer option itself is described on the product options page.

Here’s a video that shows how easy it is to use the Totalizer Options:

The totalizer option and totalizer averaging can be added to most Alicat mass flow and liquid devices ordered since 2003. Contact our applications engineers for more information about how to upgrade your unit today—get your serial numbers handy.

 

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