Steam "Wetness" in Benchtop Steriliser- Measure? 1

[SteriliserGuru]

Hi,
Excuse the ignorance, but as my job is mainly electrical & its 20 years since my thermodynamics subject, I need help. The Standards Committee in Australia is proposing that steam in benchtop sterilisers (often made by boiling water in chamber, or external small boiler, or by dry heated block with water injected into a "maze") be a maximum of 3% wet. I think that one would expect about 5% by boiling it in the chamber?... QUESTION:Is there a readilly acessible & practical method for measuring this????(Chamber is generally about 20Litres & has a 1/4 threaded test port BTW). Calibration usually involves measurement of pressure & temp. Temp to +/- 0.5C (at 134-135C) & Pressure to (supposedly 0.5% @ about 2.0-2.3 BAR). I think wetness is going to be impractical to measure , & would prefer them to allocate a pressure range by which it could vary from sat. conditions, as our main problem is insufficient air removal giving high pressures, or radiant heat off the wall giving high temp measurements...

 

[SteriliserGuru]

OK, in reply to a couple of the above posts. These are Benchtop sterilisers . There is no steam supply piped in.

The setpoint is built into the software. We can only really calibrate temp & pressure to their measured values. The aim here is really to define if given a 20L vessel of steam (no feed pipe) is there a practical way to measure the quality?
We cant really do much about the superheat or saturation I feel as much of it is inherent in any particular design. Some are heated by element wrapped around (1500W), some are heated internally (2000W coil) & a few are fed via a tiny boiler(1L) or even a hot metal brick with a maze pathway which water is injected into. (cold water into brick at about 160C) . As you can see, there is a huge disparity in the way it is made, & the resultant properties. BUT Standards australia are, I believe asking for the impossible....