The KROHNE DK 46, DK 47, DK 48 and DK 800 are variable area flow meters designed for low flow liquid and gas applications. These meters are especially well suited to measuring carrier gases in gas chromatography; for display, monitoring and dosing of gases in production processes; and for measuring liquids and gases in laboratories and pilot installations .

KROHNE DK series glass cone variable area flow meters utilize simple float technology. The measuring unit consists of a glass cone in which a float can move freely up and down. As the medium flows through the meter, the height of the float on the scale indicates the flow rate. These meters measure liquid flow rates from 0.01 to 42 gph and gas flow rates from 0.022 to 180 scfh. The different models of this series correspond to varying cone length for different accuracy requirements. For precise setting of the flow value, all devices are equipped with a metering valve .

Accuracy varies by model: DK46 is 4.0%, DK47 is 2.5%, DK48 is 1.0%, and DK800 is 2.5%. Minimum temperature is 23°F, maximum is 212°F (149°F with limit switches). Pressure rating is 145 psi for brass and stainless steel fittings, and 58 psi for PVDF fittings. The meters are simple to install and require little maintenance. It is easy to change the measuring glass, which is protected by a plastic cover, without disassembling the fitting. In applications with fluctuating operating pressure, a differential pressure regulator can be directly connected in order to ensure constant flow .