Formula Example: Converting Measurement Units of a Channel

Is your data in the wrong units? FlowWorks' FACE can fix that.

You may find that an instrument in the field is sending Imperial units when you need it in Metric, or vice versa. You could send a tech out to change the units the instrument is reporting in, if the instrument is capable of sending data in the desired measurements. But then you will have a stream of data that suddenly changes from one measurement standard to another. In this topic we’ll look at creating a calculated channel and applying a conversion, to the correct units, without requiring a trip to the field.

In this example, a user has an instrument sending flow in gallons per minute (gpm), but he wants to see the flow in liters per second (l/s).

The process for converting Channel units is twofold:

  1. Start by creating a Calculated Channel. Once complete, you will need to proceed to step 2 (which is discussed in this topic). The image below shows Channel setup for this example:

  2. Configure a FACE formula calculation that copies in data from the original Channel and applies a desired unit conversion formula (read below).

Important: These instructions are a continuation from the topic, "Creating a Calculated Channel". From step one, it is assumed that you are back at the Configure Sites Page, after having completed setup of a new Calculated Channel.

To configure FACE for the conversion formula:

  1. Starting from the Configure Sites page, locate the Calculated Channel you just created. First find the Site that the Channel resides in, then choose the Channel.
  2. Click . This will direct you to the respective page, where summarizing information on the Calculated Channel is displayed.
  3. Click . This will take you to the page where you will configure the calculation. This page has three distinct sections - the following steps take you through each part, beginning from the top of the page.
  4. Provide a Calculation Name and Description (both are optional).
  5. For Calculation Type, select Formula.
  6. Ignore Start Date and End Date. We don't want to have inconsistent data units in chunks of the data.
  7. Choose the Source Component. This is going to be the original Flow Channel that contains data that we want to convert.
  8. Define the equation. This requires that you ensure the conversion constant, which is circumstantial. For this example, we will use equation A * 0.0630901964.
  9. Click .

Now, you can use the Flow (l/s) Channel in lieu of the Flow (gpm) channel for graphing, reporting, alarming, etc. No trip to the field needed, no data stream suddenly changing units - just one nice stream of data, all in your desired units.

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