Every day, billions of gallons of wastewater are collected from our homes, businesses, and industries. Wastewater is exactly what it sounds like: water that has already been used and disposed of via a tub, toilet, sink, or storm drains. Because it is full of contaminants that make the water no longer suitable for use, it is collected in the sewer system and delivered to plants for treatment to make the water safe to be returned to the environment. Continue reading “What is Wastewater, and How is it Treated?”
Variable area flowmeters have scales calibrated for specific media at specific conditions. Most commonly, the flowmeters are calibrated for air for gas use, and water for liquid use, at standard atmospheric conditions of 70 degrees Fahrenheit and 14.7 PSIA, which is 0 PSIG. When using the flowmeter in conditions other than these standards, the flow reading will not be accurate and corrections will need to be made.
Gases can have large differences in density based on pressure and temperature. The observed reading of the flowmeter is the actual flow rate. The flow rate corrected for pressure and temperature is the standard flow rate. Often for air use the pressure in the flowmeter is not atmospheric and a correction must be made to get the standard flow rate.
For correcting the flow rate to standard use the equation shown, where actual pressure P1, actual temperature T1, and actual flow rate Q1 are used.
When using the flowmeter for gas other than air, the specific gravity must be corrected for.
For this correction use the equation shown, where actual flow rate is Q1 and gas used in the flowmeter specific gravity is SG.
If manual corrections are not desired, Dwyer offers scales calibrated for other specific media; for example, nitrogen versus air. Dwyer can even create custom scales calibrated specifically for your application media, operating pressure, and temperature. Please contact our technical sales department for already existing scales or to have your own custom scale created.