ASHTON-UNDER-LYNE, UK, Dec. 4, 2007 -- Analytical Technology Inc (ATI), a supplier of water monitoring instruments to the water and process industries, based in Ashton-under-Lyne, has chosen the Krohne DK800 variable area flowmeter to form part of a chlorine monitoring solution it is supplying to a major customer.
ATI develops and manufactures sensing technologies that monitor air and water quality. They help to improve the control of potable water and wastewater treatment. The company chose the Krohne DK800 because it needed accurate measurement at very low flow rates. The meter also needed to be robust, housed in stainless steel and be of a specific size to suit ATI's chlorine monitor. The Krohne DK800 was able to fulfill all these needs.
The DK800 flowmeter is being used to measure the flow of water over a chlorine monitor to provide the water company with an alarm if the flow rate drops below a critical level. The monitor is set to work at a flow rate of 0.5 liters per hour and the chlorine monitor alarm is set at 0.3 liters per hour.
The Krohne DK800 has an adjustable relay, which is essential to provide a rapid alarm so that operators can respond quickly to adjust the chlorine levels in the water.
As part of the specification the mount needed to be stainless steel. The DK800's stainless steel housing has a specially designed fitting to take the glass cone which offers the additional benefit of enabling replacement of the cone without replacing the whole housing. In addition, the glass version of the flow meter is the perfect size to fit the application.
Christian McTear, technical manager at ATI, said: "The DK800 variable area flowmeter is ideal for this application because it allows for local indication without the need for auxiliary power.
"Essential components can be replaced easily and the glass measuring cone also allows direct viewing of the process liquid and direct reading of the flow."
Krohne DK800 variable area flowmeters feature a conical measuring tube in which a specially shaped float moves freely up and down. The fluid flows upwards through the tube, causing the float to lift a certain distance and form a gap between tube wall and float, so that the forces acting on the float are in equilibrium.
The three forces acting on the float are the constant force of gravity, buoyancy, which according to Archimedes' principle is constant if fluid density is constant, and the upward force of the fluid flowing past the float, which depends on the flow rate.
Every measured value corresponds to a defined annular gap resulting from the conical form of the measuring tube and the specific position of the float. Because the cone is glass, the flow value can be read directly from a scale at the level of the float reading line.
Christian McTear added: "Installation and start up is simple. The flowmeter is compact and designed to be low maintenance and it is reliable, stemming from the fact that there are no wearing parts, making the DK800 extremely long-lasting."