...the more they stay the same.
Back in the very dark ages, Larry Kolbert and I shared the duties of radar product manager at what was then TN Technologies (was Texas Nuclear, now part of Thermo Scientific). TN had acquired the CannonBear radar level product line from a bunch of refugees from Fisher Controls, and we were trying to make it into a real industrial product. One of the design team, I forget who, came up with the idea that we didn't need to make the horn and the electronics out of special materials if we could shield them from the process, through some sort of window-like thing.
Thus was born the "process seal" which served to differentiate TN's radar offering until long after I left.
Now, Siemens Industry has re-introduced a similar shield, which they call a PVDF antenna.
The reasons are exactly the same as ours were in the early 1990s. Engineering problems in the process industries don't go away-- they just move to different plants and you have to figure them out all over again.
So, here's the press release:
THREADED PVDF ANTENNA OPENS UP NEW APPLICATIONS FOR SIEMENS RADAR LEVEL TRANSMITTER
ATLANTA, December 8, 2011 – Siemens’ Industry Automation Division has launched the Sitrans LR250 radar level transmitter with a new threaded PVDF (polyvinylidene fluoride) antenna for liquid and slurry measurement. The antenna opens up new applications in extreme conditions such as liquid and slurry, for this non-contacting level transmitter.
Sitrans LR250 threaded PVDF antenna is designed for extreme conditions characteristic of acids, alkalis, and other corrosive chemicals: some examples include sodium hypochlorite, sodium hydroxide, and sulfuric and hydrochloric acid applications. These applications are not suitable for stainless steel and usually require transmitters be made from exotic and costly materials. However, the Sitrans LR250 threaded PVDF antenna is able to withstand such environments while remaining a cost-effective solution. It also uses FDA-compliant materials suitable for use in food and beverage, chemical, and water treatment applications.
The Sitrans LR250 measures ranges of up to 20 m (66 ft) due to its compact 25 GHz 2-wire transmitter. It is available with Hart, Profibus PA, or Foundation Fieldbus protocols. With the graphical Quick Start Wizard, the Sitrans LR250 is operational in minutes and the infrared handheld programmer supports local programming.
Fully functional diagnostics comply with Namur NE 43 and the Sitrans LR250 has also achieved a SIL 2 functional safety declaration with Safe Failure Fraction (SFF) of 86 percent, making it suitable for use in Safety Instrumented Systems (SIS). Key fields of application for the Sitrans LR250 include bulk liquid storage tanks, process vessels with agitators, vaporous liquids and low dielectric media.
For more information, visit www.usa.siemens.com/level. Individuals interested in learning how to measure success through process instrumentation and analytics can visit www.blogs.siemens.com/measuringsuccess.