Foxboro now has a density compensating DP transmitter designed for drum level measurement. It's worth a call to your local rep....
Here is a link:
http://www.foxboro.com/NR/rdonlyres/718E1290-308E-4FA8-B059-574DA2E7E6A3/0/IMV31MultivaribleLevel.pdf
1. Open electrode
2. Shorted Electrode
3. Shorted Coil
The fact that it is reading approx. 50% of flow...those three come to mind. Check your manual for specific directions on how to test.
If it was a smaller difference..I would say check grownding or maybe somebody changed the meter factor.
What are your flow rates? Is this saturated steam? What is the pressure? What is the line size?
Vortex meters are excellant steam flow meters....but they must be sized for the entire flow range. Many just give a maximum rate, and go from there. Wrong. Have you looked at integral reducers on...
While you may not be able to actually read percentages of two phase flows, you can get accurate mass flow readings in two phase flow. Foxboro has a coriolis meter that does this. Please see:
http://www.foxboro.com/us/eng/products/instrumentation/flow/massflowmeters/digitalcoriolis.htm
Exotic level measurement solutions? Huh? RF is not what I would call "exotic".
Modern RF Admittance electronics can ignore most coatings /slime. I've seen probes in more extreme applications only be cleaned once a year or so. Of course..every application is different. Just keep an eye on it...
If it's not a "special" application my advice is to go with the one with the best support (rep, factory help, etc). I'll take support over reputation anyday.
Yes, but only if other proven technologies can't be used. Certain ultrasonic flow meter manufacturers have specific electronics designed for gas/steam flow measurement.
Thaks for the replies...
Some notes for consideration:
1. Accuracy needs to be better than +/- 2%
2. We need a compensated flow (temp and pressure)
3. The turbine meter is failing due to design. Velocity?
4. I have sized the application for an orifice plate (www.flowexpertpro.com) and it...
I have a Natural Gas flow application. Upper range flow is approx. 95000 SCFH in a 3" line. Have used turbine meters, but they do not hold up well. The only area to mount is an 8' vertical line (flow downward). Would a flow nozzle be a good fit? Line pressure is around 15psig.