KROHNE, Inc. now offers the option of surface passivation for trace-level analysis for its DK 32, DK 34, and DK 37 variable area flow meters. Passivation is an optional surface treatment for all wetted parts that helps to eliminate surface adsorption of chemically active compounds in the analyzer feed.
Trace-level analysis is used for providing evidence of very small concentrations of particles, in the range of ppm (parts per million) to ppb (parts per billion). For applications like the measurement of H2S content in natural gas or oil, mercury, or NOx/SOx flue gas analysis in various industries, it is very important that none of the particles to be detected are already adsorbed in the sample feed line. If they were, this could lead to a delayed or incorrect analysis result.
To avoid adsorption, sample feed lines, fittings and valves can be surface passivated. This can now also be applied to the DK 32, DK 34 and DK 37 all-metal purgemeters that are used for adjustment and monitoring of the sample flow to the analyser.
Before being assembled and calibrated, all metal components in contact with the medium such as cone, float, valve components, etc., receive a SilcoNert 2000 inert silicon coating, a patented surface treatment at a temperature of 400°C / 752°F. The same is possible for wetted metal components of DK 46, DK 47, DK 48 and DK 800 glass devices, as well as the H250 Variable Area flowmeter. With the addition of this inert silicon coating, surface adsorption of chemically active compounds is eliminated, thereby ensuring accurate trace-level analysis results.