ID Please.

[Bilbo]

I got given this piece of equipment and have no idea what its supposed to test for. Anyone seen one of these before.

My guess is conductivity but nothing even close to accurate.

Any information would be great. The only info on it is what you can see and it has "Made in Portugal" on the cap.

 

[dw1305]

Hi all,
Bilbo my suggestion would be conductivity, the 2 probes at the bottom don't look like a pH electrode. It will be very easy to test, put it in your RO water, it should read 0 (or pretty close), and then start adding table salt a few grains at a time. The salt will dissolve really quickly into Na+ Cl-, and the conductivity reading should rise if it stays at low values it's reading in milli-siemens, rapidly in micro-siemens. Assuming it is a conductivity meter, and sensitive enough to be useful, the calibration solution is 0.745g of KCl ("sodium free salt") in 1 litre (1000 ml) of R.O water, which has a conductivity of 1411microS at 25oC. This solution is fairly stable and will keep for at least a year.
cheers Darrel

 

[tjudy]

Conductivity. That looks like a generic version of the meter sold by Milwaukee meters. They are made in Asia somewhere, and I am sure that they are available from other sources than Milwaukee.

 

[Bilbo]

Thanks DW.

I tried RO water and the reading came up to 11 (Somethings) so I changed to Millipore. The MilliQ unit display said 18.2 uS at 25c and my meter was reading 1.6 - 2.2 so Im thinking maybe uS multiplied by 10?

The unit wont display anything over 99 so the mix of KCL went off the chart and gave an error, Standard tapwater also went over limit so I will try your calibration recipe at a 10% dilution to see what happens.

Thanks so far for your help. Whatever this thing is its very very sensitive.
1/10 tsp of salt (NaCl) in a 100mls of RO water is out of range.

Would love to find out who makes it and what instructions are avaliable for it. Google Pix show simillar ones by Hanna and by Milwaukee (Thanks TJudy for helping me find that)

 

[dw1305]

Hi all,
Bilbo you can try serial dilution of the stock solution (1 in 10 or 1 in 100), the scale is linear, so you don't need a standard curve, however it is temperature dependent.

Ted looks "on the money"
<http://www.milwaukeemeters.com.au/MILWAUKEE%20STANDARDS/milwaukee.htm>, but it would depend which meter as to how useful it is. Calibration is by turning a small screw, probably best on the 1 in 10 dilution of the stock solution.

The (1 in 10) 141 microS and the 14.1 microS solutions are not as stable, but will keep for several days.

cheers Darrel