On 28/08/2023 00:37 Pipl penned these words:
> On 26 Aug 2023 19:37:35 GMT, "sweller" <sweller@mztech.fsnet.co.uk>
> wrote:
>
>> geoffC wrote:
>>
>>> Next time you defrost the fridge/freezer.....
>>
>> Does anyone do that anymore? My one does it itself.
>
> We do, though that is partly due to the door not always being closed
> properly.
>

The upright sorts itself out, the chest freezer needs doing a couple of times a
year.
--
Ian

"Man will never be free until the last king is strangled with the entrails of
the last priest"

You might start out by getting a cheap water resistivity meter,
often called a total dissolved solids meter. It will at least
give a hint of ion concentrations. The purest water has a resisivity
of about 14 megohm-centimeters, seawater is about 20 ohm-cm.

I once asked a materials science guy how to make pure water.

He just smiled and said there was no such thing. All water is
contaminated with something. The best one can do is find water
contaminated with things that don't cause trouble.

Mechanical filters only remove insoluble particles.

Reverse osmosis lets some ions through. Larger stuff too, if
there's even a single pinhole in the membrane. Soluble organics,
at least sometimes, can diffuse through the membranes.

Deionization progressively lowers ion concentration but imperfectly
regenerated resin beds can release lots of regenerant chemicals,
while doing nothing about particles and organics.

Distillation suffers from spray carryover from the boiler and
adds any condenser materials that form soluble materials with
the condensate. Organics distill along with the water, at a
concentration dependent on condensation temperature.

Activated carbon generally removes organics but little else.

The steps used in semiconductor plants are something like

1. mechanical filtration
2. softening, to replace calcium and magnesium with sodium
3. reverse osmosis, to remove the majority of sodium
4. carbon filtration, to remove organics
5. deionization, to remove residual sodium and CO2

Next the water goes into a "polishing loop" that circulates
through the plant and passes through freshly-regenerated
deionizer and carbon beds, to clean up whatever leaches out
of the piping. Those beds are shifted to dirtier parts of
the system until exhausted, then sent out for regeneration.
These days a high-power UV lamp is often added to decompose
organics as well.
The key is careful monitoring. No method makes clean water
without attention to maintenance.

Thanks for reading,

bob prohaska

On Wed, 30 Aug 2023 21:31:59 -0000 (UTC), bob prohaska
<bp@www.zefox.net> wrote:

>You might start out by getting a cheap water resistivity meter,
>often called a total dissolved solids meter. It will at least
>give a hint of ion concentrations. The purest water has a resisivity
>of about 14 megohm-centimeters, seawater is about 20 ohm-cm.
>
>I once asked a materials science guy how to make pure water.
>
>He just smiled and said there was no such thing. All water is
>contaminated with something. The best one can do is find water
>contaminated with things that don't cause trouble.

<snip>

Fascinating!

--
Colin Irvine
FJR1300A

sweller wrote:
> > https://www.spotlesswater.co.uk/locations/ is apparently much cheaper
> > than that, if you have one near you. No idea how much you have to take
> > to get it for the 3.5p/l they advertise, though.
> About 20 miles away - I wonder if they'll sell me 10 litres at a time!

When I was regularly having to drain the race bike, I ordered 25 liters from these guys:

https://apcpure.com/product/distilled-water/

On 8/31/2023 9:53 AM, Colin Irvine wrote:
> On Wed, 30 Aug 2023 21:31:59 -0000 (UTC), bob prohaska
> <bp@www.zefox.net> wrote:
>
>> You might start out by getting a cheap water resistivity meter,
>> often called a total dissolved solids meter. It will at least
>> give a hint of ion concentrations. The purest water has a resisivity
>> of about 14 megohm-centimeters, seawater is about 20 ohm-cm.
>>
>> I once asked a materials science guy how to make pure water.
>>
>> He just smiled and said there was no such thing. All water is
>> contaminated with something. The best one can do is find water
>> contaminated with things that don't cause trouble.
>
> <snip>
>
> Fascinating!
>
+1

--
The erstwhile Thomas
FJR1300, R1200GS & ST1100 (in memoriam)

On Thu, 31 Aug 2023 10:50:37 -0700, Turby <xsurf@xmail.com> wrote:

>On 8/31/2023 9:53 AM, Colin Irvine wrote:
>> On Wed, 30 Aug 2023 21:31:59 -0000 (UTC), bob prohaska
>> <bp@www.zefox.net> wrote:
>>
>>> You might start out by getting a cheap water resistivity meter,
>>> often called a total dissolved solids meter. It will at least
>>> give a hint of ion concentrations. The purest water has a resisivity
>>> of about 14 megohm-centimeters, seawater is about 20 ohm-cm.
>>>
>>> I once asked a materials science guy how to make pure water.
>>>
>>> He just smiled and said there was no such thing. All water is
>>> contaminated with something. The best one can do is find water
>>> contaminated with things that don't cause trouble.
>>
>> <snip>
>>
>> Fascinating!
>>
>+1

+2

--

-Pip

Colin Irvine <look@colinandpat.co.uk> wrote:
> On Wed, 30 Aug 2023 21:31:59 -0000 (UTC), bob prohaska
> <bp@www.zefox.net> wrote:
>
>>You might start out by getting a cheap water resistivity meter,
>>often called a total dissolved solids meter. It will at least
>>give a hint of ion concentrations. The purest water has a resisivity
>>of about 14 megohm-centimeters, seawater is about 20 ohm-cm.
>>
>>I once asked a materials science guy how to make pure water.
>>
>>He just smiled and said there was no such thing. All water is
>>contaminated with something. The best one can do is find water
>>contaminated with things that don't cause trouble.
>
> <snip>
>
> Fascinating!

Bob's one of the good guys from reeky. I hope he pops in once in a
while here.

--
FJR1300A, GL1000, KLR650A6F, EX250J9A, DR200SE, Vespa Ciao

El Wed, 30 Aug 2023 21:31:59 +0000, bob prohaska escribió:

> You might start out by getting a cheap water resistivity meter, often
> called a total dissolved solids meter. It will at least give a hint of
> ion concentrations. The purest water has a resisivity of about 14
> megohm-centimeters, seawater is about 20 ohm-cm.

Mine measures microsiemens per cm or somesuch. I just know that drinking
water has to be below 2,500.

--
Paul.

https://paulc.es

On 31/08/2023 23:25, Mark Olson wrote:
> Colin Irvine <look@colinandpat.co.uk> wrote:
>> On Wed, 30 Aug 2023 21:31:59 -0000 (UTC), bob prohaska
>> <bp@www.zefox.net> wrote:
>>
>>> You might start out by getting a cheap water resistivity meter,
>>> often called a total dissolved solids meter. It will at least
>>> give a hint of ion concentrations. The purest water has a resisivity
>>> of about 14 megohm-centimeters, seawater is about 20 ohm-cm.
>>>
>>> I once asked a materials science guy how to make pure water.
>>>
>>> He just smiled and said there was no such thing. All water is
>>> contaminated with something. The best one can do is find water
>>> contaminated with things that don't cause trouble.
>>
>> <snip>
>>
>> Fascinating!
>
> Bob's one of the good guys from reeky. I hope he pops in once in a
> while here.
>

Reads like he does/used to work in the semiconductor industry. I wonder
where. I've been to quite a few fabs in the US.

I do recall they use vast quantities of water and lots of other fewer
safe checmicals.

--
/Simon

On 31/08/2023 23:25, Mark Olson wrote:
> Colin Irvine <look@colinandpat.co.uk> wrote:
>> On Wed, 30 Aug 2023 21:31:59 -0000 (UTC), bob prohaska
>> <bp@www.zefox.net> wrote:
>>
>>> You might start out by getting a cheap water resistivity meter,
>>> often called a total dissolved solids meter. It will at least
>>> give a hint of ion concentrations. The purest water has a resisivity
>>> of about 14 megohm-centimeters, seawater is about 20 ohm-cm.
>>>
>>> I once asked a materials science guy how to make pure water.
>>>
>>> He just smiled and said there was no such thing. All water is
>>> contaminated with something. The best one can do is find water
>>> contaminated with things that don't cause trouble.
>>
>> <snip>
>>
>> Fascinating!
>
> Bob's one of the good guys from reeky. I hope he pops in once in a
> while here.
>

Reads like he does/used to work in the semiconductor industry. I wonder
where. I've been to quite a few fabs in the US.

I do recall they use vast quantities of water and lots of other fewer
safe checmicals.

--
/Simon

On 01/09/2023 11:58, Paul Carmichael wrote:
> El Wed, 30 Aug 2023 21:31:59 +0000, bob prohaska escribió:
>
>> You might start out by getting a cheap water resistivity meter, often
>> called a total dissolved solids meter. It will at least give a hint of
>> ion concentrations. The purest water has a resisivity of about 14
>> megohm-centimeters, seawater is about 20 ohm-cm.
>
> Mine measures microsiemens per cm or somesuch. I just know that drinking > water has to be below 2,500.
>

He said "microsiemens". <Snigger>. So, less than 10cc?

--
/Simon

On Friday, 1 September 2023 at 15:21:17 UTC+1, siwilson wrote:
> On 01/09/2023 11:58, Paul Carmichael wrote:
> > El Wed, 30 Aug 2023 21:31:59 +0000, bob prohaska escribió:
> >
> >> You might start out by getting a cheap water resistivity meter, often
> >> called a total dissolved solids meter. It will at least give a hint of
> >> ion concentrations. The purest water has a resisivity of about 14
> >> megohm-centimeters, seawater is about 20 ohm-cm.
> >
> > Mine measures microsiemens per cm or somesuch. I just know that drinking > water has to be below 2,500.
> >
> He said "microsiemens". <Snigger>. So, less than 10cc?

'A handful of dust'

(might re-read that).

siwilson <siwilson@nodamnspamn.hotmail.com> wrote:
>
> Reads like he does/used to work in the semiconductor industry. I wonder
> where. I've been to quite a few fabs in the US.

Not in the industry, rather on the very far fringes. In the mid-1990's
was a brief stint at a factory that made IC-packaged quartz crystals,
then a few years later in a material science lab and finally at a
university fab. It's a fascinating process, but I got into it too
late for it to be much fun.
> I do recall they use vast quantities of water and lots of other fewer
> safe checmicals.

The crystal plant was interesting in that they re-cycled most of their
wastewater, cleaning it back up and putting it back into process. The
chemistry of quartz crystals is simple, the part value is low and the
sensitivity to contamination relatively low.

Semiconductors are both much more sensitive to contamination and vastly
more valuable, especially in 12 inch wafers. I'd be rather surprised
if a modern fab recycled process water for anything beyond watering the
landscaping outside. If you know of any that do please indicate!

Thanks for reading,

bob prohaska