HM digital tds pen meter help please

[MrStickyScissors]

I bought this meter from the hydro store and they dont even know how the fuck to use it so im wondering if anyone has any info on it. it has different setting nacl, 442, kcl. now i guess these are conversions but theres these 3 settings under ppm and the other mode is a upside down h and a s. if the ppm mode reads 400 and I switch to the other mode it reads 800.

 

[doc111]

I bought this meter from the hydro store and they dont even know how the fuck to use it so im wondering if anyone has any info on it. it has different setting nacl, 442, kcl. now i guess these are conversions but theres these 3 settings under ppm and the other mode is a upside down h and a s. if the ppm mode reads 400 and I switch to the other mode it reads 800.

Yeah, I've asked numerous people, even hydro shop owners and employees, and nobody can tell me what the hell the different modes are for. I just kept it on whatever mode it was set on when I got it.

 

[Spanishfly]

I bought this meter from the hydro store and they dont even know how the fuck to use it.

So what did you intend to use it for?? LOL

Presumably NaCl and KCl are sodium and potassium chloride respectively. Good luck.

 

[doc111]

So what did you intend to use it for?? LOL

Presumably NaCl and KCl are sodium and potassium chloride respectively. Good luck.

Yes, but those are the modes on some of those TDS meters and the instruction booklets don't tell you what mode you should be using with what kind of water. I have been to 2 different hydro shops and nobody could tell me what the different modes are actually for. Obviously, NaCl is Sodium Chloride and KCl is Potassium Chloride but what does that mean for the different modes? Do you have an answer for us because I would like to know the answer to this one as well?

 

[MrStickyScissors]

yeah an answer would be nice. one mode is reads way higher than the other

 

[jackholexxxx]

I have the HM Digital COM-100 and had the same questions. KCl is what you want (except under special circumstances).

From the COM-100 manual:

KCl: Potassium Chloride is the international standard to calibrate instruments that measure conductivity. The COM-100 is factory calibrated with a 1413 micro-seimens solution is the default mode is EC-KCl.

442: Developed by the Myron L Co., 442 simulates the properties of natural water (rivers, lakes, wells, drinking water, etc.) with a combination of 40% Sodium Bicarbonate, 40% Sodium Sulfate and 20% Chloride.

NaCl: Sodium Chloride is used in water where the predominate ions are NaCl, or whose properties are similar to NaCl, such as seawater and brackish water.

As to your queston of EC vs TDS(ppm) the manual has this to say:

Electrical Conductivity (EC) and Total Dissolved Solids (TDS) Overview: While EC and TDS are often used synonymously, there are important differences to note. EC, when applied to water, refers to the electrical charge of a given water sample. TDS refers to the total amount of substances in the water other than the pure H2O. The only true way of measuring TDS is to evaporate the water and weigh what’s left. Since this is near impossible to do for the average person, we can estimate the TDS level by measuring the EC of the water. Every digital TDS meter in the world is actually an EC meter.

So it depends on what you want to measure. Most of the numbers I see around here are in TDS(ppm). So setting your meter to TDS with KCl conversion will allow you to compare your numbers with what is most often posted here.

 

[MrStickyScissors]

I have the HM Digital COM-100 and had the same questions. KCl is what you want (except under special circumstances).

From the COM-100 manual:



As to your queston of EC vs TDS(ppm) the manual has this to say:



So it depends on what you want to measure. Most of the numbers I see around here are in TDS(ppm). So setting your meter to TDS with KCl conversion will allow you to compare your numbers with what is most often posted here.

thanks a bunch man that hella helps.