Conductivity settings on Profilux Plus II eX

[Phxkeller]

So when I get to the point of using the calibration fluid the profilux ask for the 1.0217 calibration fluid to be used 50ms/25'C - psu 29.50, what the profilux came with.

I'm not able to adjust this setting but should't 50ms/25'C be a salinity of 1.0246 - psu 2.80??

If so this setting may be the issue and not the calibration fluids.. But I'm not the expert and that is why I'm asking for someone with the knowledge to confirm or let me know what else I could be doing wrong..

Thanks for all your time!! I appreciate it very much.

Frank

 

[elzool]

I am by no means an expert, but this table from American Marine is what I always have used.

They show 1.0217 equaling 45.5 mS so maybe you are on to something Frank.

 

[Phxkeller]

elzool - Thanks for the new solution today!! I really appreciate the help!

Still no luck.. The reading is now closer than before but not like it should be..

Hope everyone has a SAFE HAPPY Holiday and NEW YEAR!!

Frank

 

[AQD_ottawa]

Hiya

Please see my post in the other conductivity thread save me copying and pasting.

You will find new info there to help you.
Happy holidays
Michael

 

[Phxkeller]

Clarifications with the #'s

Clarifications with the #'s

Not to beat a dead animal or anything but would you clarify the above #'s Michael.

Why does the profilux controller ask for 1.0217 solution if that is not actually = to 50ms? more like 45ms.

Thanks for the help in understanding this issue.

Frank

 

[AQD_ottawa]

the solution was designated Before the specific gravity reading was made available.

I assume you have not tried calibrating your refract with 50ms?

What does the 50ms read on the read glass of your refract? It should also have an MS scale.

This dialogue will never be resolved until this is tested, so I will do it in the new year and publish the results.

Please wait for my reply on the 6th Jan as to what reading we get with GHL calibration against an array of refractometers.

I hope this info helps and apologies that I cant give you answers before then as I am not in Canada but on holiday in the UK right now over Christmas.

 

[Matthias Gross]

Now I see what you mean! ProfiLux displays salinity or density and not conductivity while calibrating if you choosed another display then conductivity! That does not make sense and is irritating, of course.
I will change this in 3.07.

Please calibrate with 50mS (or any other value you choosed before, but 50mS is standard for our fluid) and ignore what ProfiLux displays during calibration!

 

[Matthias Gross]

version 3.07 is available:
http://www.ghl-kl.de/Produkte/Aquaristik/Download/AllProfiLuxII_V307.zip

I changed the displayed values during calibration as written above, I hope confusion ends now.

Furthermore I made slight changes in the calculation algorithms (conductivity to density and salinity) - 10 digits after decimal point for the internal calculation. This should be more precisely as necessary.

I checked a lot of tables and came to the result that values (density and salinity based on conductivity) vary from table to table. The algorithms in ProfiLux assume an "average table".
Please give me feedback if the readings are better now.

One more hint: Temperature compensation is very important for these calculations. Make sure that temperature probe and conductivity probe are near to each other.

 

[Phxkeller]

Michael and Matthias Thanks for all your input and listening to the info above.. What a great (outstanding) job of customer service you provide makes me very pleased I went with the profilux!!

Ok Heres my latest findings...

I calibrated the profilux with a MS of 59.2 which then the profilux asked for the 1.0262 calibration solution which is what I am using pinpoint 53MS solution. I also used this solution to set my refractometer at 1.026. Once this was complete both the refractometer and the profilux read 1.024... Exactly together and where my range is for my tank.

Don't know if this helps as far as info .. But I'm glad to zero in my profilux to read without having to figure I'm going to live with being off a bit.

 

[AQD_ottawa]

Hiya
Back in Canada now, normal service resumes tomorrow!

Many thanks for your kind message, we both strive to make sure every user gets the best support available and we will continue to listen to what our clients want constantly, it is only with the input from users that we can develop the best aquatic controller on the market.

 

[jdjeff58]

I had the same issue with the calibration fluid. I brought that up back in the early summer 2007. I ended up getting the Pinpoint 53ms and a Milwaukee ATC refract. That's what finally worked for me also. The conductivity solution that I got with the profilux wasn't even close. I also made up some solution where I work @50mS...and that checked out as well. Don't forget to calibrate @ 25°C

 

[AQD_ottawa]

We have had some interesting emails about solutions not being accurate but as yet have not heard how people are coming to this assumption. We have tested numerous samples on nearly every meter possible and as yet have found no discrepencies. i ahve replied to everyone but never had a response back.

One thing to note - contamination and evaporation will change the reading of the solution

We have had great feedback with this intersting subject.

 

[jdjeff58]

The only way I was able to draw my conclusion was to have a second instrument to compare my results. It was the refractometer that revealed the discrepency. I had a long conversation with the Milwaukee rep. concerning the proper calibration of the refract. Once I straigtened that out, the refract. was my reference. Everything I threw at the refract. was reading as advertised...including my pharmaceutical grade mixture. Everything but the brand new (out of the box) profilux solution, that is. I triple verified my calibration and ended up tossing the profilux solution in the trash. I calibrate industrial grade conductivity probes at a pharmaceutical company and I knew something didn't look right from the beginning. I was mixing a batch of saltwater at 53mS with the help of my refract. and the Pinpoint 53mS solution. And yet the Profilux solution was giving me consistent 45mS calibrations. Not sure what else to say other than I agree with you that the solution may have gotten contaminated somehow or it was a bad batch. But my solution was brand new along with my probe.

I did bring this to the attention of Matthias thru Aq. Specialty back in may or june of 2007. But I was satisfied that I had the issue ironed out...so I really didn't persue it any further.

As for the pH and redox. The pH is right on the money and the redox I never verified. But I wasn't too concerned with the redox since it is only a reference point anyway.

 

[Matthias Gross]

I remember this case. Be assured we take random samples from all our calibration fluids - we never had a solution out of the tolerance in the past. All our fluids come from a certified German company which produces these things for the industry.

Especially the calibration fluid for conductivity must be measured with highest care because the conductivity depends extremely on the temperature. Profilux has a temperature compensation, but it works only accurately if the measured temperature is correct. That's why the fluid must have a well known temperature during calibration and the temperature must be measured nearby the conductivity probe during normal operation.

 

[jdjeff58]

<a href=showthread.php?s=&postid=11504320#post11504320 target=_blank>Originally posted</a> by Matthias Gross
version 3.07 is available:
http://www.ghl-kl.de/Produkte/Aquaristik/Download/AllProfiLuxII_V307.zip

I changed the displayed values during calibration as written above, I hope confusion ends now.

Furthermore I made slight changes in the calculation algorithms (conductivity to density and salinity) - 10 digits after decimal point for the internal calculation. This should be more precisely as necessary.

I checked a lot of tables and came to the result that values (density and salinity based on conductivity) vary from table to table. The algorithms in ProfiLux assume an "average table".
Please give me feedback if the readings are better now.

I'm still currently running 3.05 firmware. If I update to 3.08, will my conductivity calibration be off with the imported calibration data? I'm not sure I understand what you mean by "if the readings are better now". If I'm already referencing my probe to a refractometer and the refract. is accurate, won't it throw off my salinity reading with the new algorithms? Maybe I'm not understanding something here. Could you elaborate? Thanks.

One more hint: Temperature compensation is very important for these calculations. Make sure that temperature probe and conductivity probe are near to each other.

 

[Matthias Gross]

correct - after update your readings may differ slightly.