As the ph goes down, it would be more alkaline, up is acidic.
7.0 is neutral. I would try toyota SLLC (super long life coolant).
It seems to last ten years or more in cars...
Sent from my iPad
> On Mar 6, 2017, at 11:32, Jeff DePolo <jd0@broadsci.com> wrote:
>
>
>> ## IF conductivity is NOT an issue, then Id suggest using
>> what is already
>> being used in car eng radiator setups. Distilled water + a
>> corrosion inhibitor.
>> Typ a 50-50 mix of glycol + distilled water is used. The
>> glycol offers the
>> inhibitor properties, and also raises the boiling point by a
>> bunch, to typ 265 deg F,
>> IF under typ pressure of 10-15 psi. Less, with lower
>> pressure, but still more than
>> 212 deg F. That 50-50 mix will also lower the freezing
>> point to aprx -40 deg F.
>> You can also buy the 50-50 premixed, just pour it in.
>
> I agree.
>
> In liquid-cooled broadcast transmitters (both tube and solid-state), the
> thermal transfer fluid is typically a 50/50 mix of distilled water and
> Dowtherm SR-1. SR-1 is ethylene glycol with corrosion inhibitors. There
> are a few manufacturers that recommend or specify something else; Rohde and
> Schwarz comes to mind - they spec DEX-COOL for some of their rigs (and,
> yeah, I know all of the GM DEX-COOL horror stories, though I've never
> experienced any problems myself either in broadcast transmitters nor in my
> own GM vehicles).
>
> 50/50 is a good all-around mix ratio for SR-1. It provides freeze
> protection down to around -35 degrees F, yields a healthy concentration of
> corrosion inhibitors, and prevents bacterial growth/contamination.
>
> Unless there is some anomaly that occurs during the life of the coolant that
> results in contamination, the primary reason to replace coolant at regular
> intervals is due to the natural change in pH. When the system is initially
> filled, the pH of the 50/50 glycol mix is about 9.3. As the glycol ages,
> and as the copper and aluminum in the plumbing and system components leach
> into the coolant, the pH slowly falls. We usually do a flush when the pH
> falls below 8.0, and we never ever let it go below 7.5. You don't want to
> let it turn acidic. While you can try to extend the lifespan of the coolant
> by adding KOH to raise the pH, by the time the pH starts gets down near 8.0,
> the corrosion inhibitors are likely nearing depletion anyway.
>
> You can send a fluid sample out to a lab for testing of all the main
> indicators of the health of the coolant (glycol concentration, pH, inhibitor
> concentration, contaminants, etc.) -- probably overkill for ham amplifiers.
> Dow will even do it for free if your system is large enough (as I recall, if
> the volume of coolant in the system is over 200 gallons they do it for
> nothing). But, for home/ham use, I think that if you just do a visual on
> the coolant to confirm it's the proper color and free of contaminants, and
> you check the pH every few months and when it falls below 8.0 do a flush and
> re-fill, you would be fine.
>
> By the way, cleaning the system real well before the first fill is very
> important. A solution of a few percent TSP in distilled water is typically
> used, and then flushed twice with distilled water before filling the system
> with the 50/50 mix.
>
> The usual disclaimers apply regarding the toxicity of ethylene glycol, the
> proper disposal of the same, yada yada yada.
>
> --- Jeff WN3A
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|