Fwd: Re: Feature request - min temp and max temp options to display in dive log listing

[matt wilbur via subsurface]

 Forwarded Message From : matt@efs.orgTo : 
willemfergu...@proton.mecc : douglas.junk...@gmail.com,helling@atdotde.deDate : 
Mon, 14 Aug 2023 14:59:49 -0700Subject : Re: Feature request - min temp and max 
temp options to display in dive log listing Forwarded Message 
These are all great points, and ive seen the lag in temp 
measurements as well.. every dive :). But just like subsurface just accepts the 
min temp as gospel, even though it's possible there is measurement lag 
happening, for my purposes and for my reef.org surveys, what my computer 
measures as max temp, right or wrong or really wrong, is just fine.So I guess 
to clarify the suggestion, id like to be able to display the measured max temp. 
Just like it displays the measured min temp. No accounting for measurement 
inaccuracies.Better is the enemy of good enough :-)they have mountains of data 
collected using max recorded temp of dive computers and for what they need and 
the ranges they work in, its fine.thanks!!matt  On Mon, 14 Aug 2023 
14:16:00 -0700  subsurface@subsurface-divelog.org  wrote An attractive 
idea, Doug, but I suspect things are more complex. The water medium seldom has 
a single temperature with a single associated lag. As we dive through 
thermoclines the Dive computer is probably going through different lag periods 
dependent on the delta t between computer and water. Furthermore there are 
equipment limitations concerning the accuracy of temperature measurements by 
dive computers, depending on the thermal mass of the computer and a miriad of 
electronic characteristics of the equipment. Dive computers were just not made 
for accurate temperature measurements (depending on one's definition of 
'accurate'). For serious work, one would need a purpose built water temperature 
logger. Then one can define Max and Min temperature in a way it makes sense 
within the objectives of the work. Water temp is not an independent and 
universal variable. It reflects the complex interaction between environment and 
the water medium. To compare two water temperatures is therefore not a trivial 
issue. Kind regards, willem. Sent from Proton Mail mobile Original 
Message On 14 Aug 2023, 22:21, Doug Junkins via subsurface < 
subsurface@subsurface-divelog.org> wrote:On Aug 14, 2023, at 11:58 AM, Robert 
Helling via subsurface  wrote:Matt,On 14. 
Aug 2023, at 19:24, Matt Wilbur via subsurface 
 wrote:I'm not sure this is a feasible 
request for mobile subsurface, but on mac I frequently use subsurface, and I'm 
also doing surveys on every dive for reef.org (I've done about 120 since may). 
We have to report max and min temps in our surveys so they can hopefully 
correlate temps with the critters and locations we find them in.Would it be 
possible to adjust the "Temp." displayed with the dives in the dive log and the 
"Water Temp." in the info display to show a min and max water temp?  So I could 
just have my dive listing show me my min and max temps so I don't have to mouse 
over the dive profile plot to read the max temp on the dive?Whether this is 
doable or not, thank you SO MUCH for the fantastic open source dive logging 
app. I thought I might take a crack at adding a max temp field to display since 
the data is all in there - but lost my steam with the info "Water temp." 
display possibly needing to be changed too.the problem with this is that the 
typical temperature sensors on dive computers are very slow. At the start of 
the dive, the dive computer probably is at the surface air temperature and only 
slowly (except for dives in mid winter freezing temperatures) cools down to the 
water temperature. Thus I would not expect that for the first few minutes of 
the dive, the recorded temperature is actually the ambient water temperature. 
So what you would be recording as the max temperature is probably much more 
related to the surface air temperature (which we log if the dive computer 
reports it).On the other hand, the dive temperature that is shown in the dive 
list (you realise you can change the fields that are displayed there and their 
order) is the minimum temperature.At some point, I tried plotting the 
temperature against depth (rather than against time). I was hoping to see 
things there like thermoclines but that did not work exactly for the reason of 
inertia of the temperature sensor.I was thinking about the lag issue as well. 
Maybe one way to do it is to cut off the first 5-10 minutes of temperature 
samples before doing the Min/Max calculation. It could even be a configuration 
option for how many minutes of temperature samples to ignore in the calculation 
so people that really want this info can customize it based on their own dive 
computer. Just my $0.02.-Doug___
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Re: Feature request - min temp and max temp options to display in dive log listing

[tormento via subsurface]

Supposing that the delay is linear, what about a time offset setting?

Alberto

Il giorno lun 14 ago 2023 alle 20:59 Robert Helling via subsurface <
subsurface@subsurface-divelog.org> ha scritto:

> Matt,
>
> On 14. Aug 2023, at 19:24, Matt Wilbur via subsurface <
> subsurface@subsurface-divelog.org> wrote:
>
> I'm not sure this is a feasible request for mobile subsurface, but on mac
> I frequently use subsurface, and I'm also doing surveys on every dive for
> reef.org (I've done about 120 since may). We have to report max and min
> temps in our surveys so they can hopefully correlate temps with the
> critters and locations we find them in.
>
> Would it be possible to adjust the "Temp." displayed with the dives in the
> dive log and the "Water Temp." in the info display to show a min and max
> water temp?  So I could just have my dive listing show me my min and max
> temps so I don't have to mouse over the dive profile plot to read the max
> temp on the dive?
>
> Whether this is doable or not, thank you SO MUCH for the fantastic open
> source dive logging app. I thought I might take a crack at adding a max
> temp field to display since the data is all in there - but lost my steam
> with the info "Water temp." display possibly needing to be changed too.
>
>
> the problem with this is that the typical temperature sensors on dive
> computers are very slow. At the start of the dive, the dive computer
> probably is at the surface air temperature and only slowly (except for
> dives in mid winter freezing temperatures) cools down to the water
> temperature. Thus I would not expect that for the first few minutes of the
> dive, the recorded temperature is actually the ambient water temperature.
> So what you would be recording as the max temperature is probably much more
> related to the surface air temperature (which we log if the dive computer
> reports it).
>
> On the other hand, the dive temperature that is shown in the dive list
> (you realise you can change the fields that are displayed there and their
> order) is the minimum temperature.
>
> At some point, I tried plotting the temperature against depth (rather than
> against time). I was hoping to see things there like thermoclines but that
> did not work exactly for the reason of inertia of the temperature sensor.
>
> Best
> Robert
>
> ___
> subsurface mailing list
> subsurface@subsurface-divelog.org
> http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
>
___
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Re: Feature request - min temp and max temp options to display in dive log listing

[Willem Ferguson via subsurface]

An attractive idea, Doug, but I suspect things are more complex. The water 
medium seldom has a single temperature with a single associated lag. As we dive 
through thermoclines the Dive computer is probably going through different lag 
periods dependent on the delta t between computer and water. Furthermore there 
are equipment limitations concerning the accuracy of temperature measurements 
by dive computers, depending on the thermal mass of the computer and a miriad 
of electronic characteristics of the equipment. Dive computers were just not 
made for accurate temperature measurements (depending on one's definition of 
'accurate'). For serious work, one would need a purpose built water temperature 
logger. Then one can define Max and Min temperature in a way it makes sense 
within the objectives of the work. Water temp is not an independent and 
universal variable. It reflects the complex interaction between environment and 
the water medium. To compare two water temperatures is therefore not a trivial 
issue. Kind regards, willem.

Sent from Proton Mail mobile

 Original Message 
On 14 Aug 2023, 22:21, Doug Junkins via subsurface wrote:

>> On Aug 14, 2023, at 11:58 AM, Robert Helling via subsurface 
>>  wrote:
>>
>> Matt,
>>
>>> On 14. Aug 2023, at 19:24, Matt Wilbur via subsurface 
>>>  wrote:
>>>
>>> I'm not sure this is a feasible request for mobile subsurface, but on mac I 
>>> frequently use subsurface, and I'm also doing surveys on every dive 
>>> for[reef.org](http://reef.org/)(I've done about 120 since may). We have to 
>>> report max and min temps in our surveys so they can hopefully correlate 
>>> temps with the critters and locations we find them in.
>>>
>>> Would it be possible to adjust the "Temp." displayed with the dives in the 
>>> dive log and the "Water Temp." in the info display to show a min and max 
>>> water temp? So I could just have my dive listing show me my min and max 
>>> temps so I don't have to mouse over the dive profile plot to read the max 
>>> temp on the dive?
>>>
>>> Whether this is doable or not, thank you SO MUCH for the fantastic open 
>>> source dive logging app. I thought I might take a crack at adding a max 
>>> temp field to display since the data is all in there - but lost my steam 
>>> with the info "Water temp." display possibly needing to be changed too.
>>
>> the problem with this is that the typical temperature sensors on dive 
>> computers are very slow. At the start of the dive, the dive computer 
>> probably is at the surface air temperature and only slowly (except for dives 
>> in mid winter freezing temperatures) cools down to the water temperature. 
>> Thus I would not expect that for the first few minutes of the dive, the 
>> recorded temperature is actually the ambient water temperature. So what you 
>> would be recording as the max temperature is probably much more related to 
>> the surface air temperature (which we log if the dive computer reports it).
>>
>> On the other hand, the dive temperature that is shown in the dive list (you 
>> realise you can change the fields that are displayed there and their order) 
>> is the minimum temperature.
>>
>> At some point, I tried plotting the temperature against depth (rather than 
>> against time). I was hoping to see things there like thermoclines but that 
>> did not work exactly for the reason of inertia of the temperature sensor.
>
> I was thinking about the lag issue as well. Maybe one way to do it is to cut 
> off the first 5-10 minutes of temperature samples before doing the Min/Max 
> calculation. It could even be a configuration option for how many minutes of 
> temperature samples to ignore in the calculation so people that really want 
> this info can customize it based on their own dive computer. Just my $0.02.
>
> -Doug___
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Re: Feature request - min temp and max temp options to display in dive log listing

[Doug Junkins via subsurface]

> On Aug 14, 2023, at 11:58 AM, Robert Helling via subsurface 
>  wrote:
> 
> Matt,
> 
>> On 14. Aug 2023, at 19:24, Matt Wilbur via subsurface 
>>  wrote:
>> 
>> I'm not sure this is a feasible request for mobile subsurface, but on mac I 
>> frequently use subsurface, and I'm also doing surveys on every dive for 
>> reef.org  (I've done about 120 since may). We have to 
>> report max and min temps in our surveys so they can hopefully correlate 
>> temps with the critters and locations we find them in.
>> 
>> Would it be possible to adjust the "Temp." displayed with the dives in the 
>> dive log and the "Water Temp." in the info display to show a min and max 
>> water temp?  So I could just have my dive listing show me my min and max 
>> temps so I don't have to mouse over the dive profile plot to read the max 
>> temp on the dive?
>> 
>> Whether this is doable or not, thank you SO MUCH for the fantastic open 
>> source dive logging app. I thought I might take a crack at adding a max temp 
>> field to display since the data is all in there - but lost my steam with the 
>> info "Water temp." display possibly needing to be changed too.
> 
> the problem with this is that the typical temperature sensors on dive 
> computers are very slow. At the start of the dive, the dive computer probably 
> is at the surface air temperature and only slowly (except for dives in mid 
> winter freezing temperatures) cools down to the water temperature. Thus I 
> would not expect that for the first few minutes of the dive, the recorded 
> temperature is actually the ambient water temperature. So what you would be 
> recording as the max temperature is probably much more related to the surface 
> air temperature (which we log if the dive computer reports it).
> 
> On the other hand, the dive temperature that is shown in the dive list (you 
> realise you can change the fields that are displayed there and their order) 
> is the minimum temperature.
> 
> At some point, I tried plotting the temperature against depth (rather than 
> against time). I was hoping to see things there like thermoclines but that 
> did not work exactly for the reason of inertia of the temperature sensor.

I was thinking about the lag issue as well. Maybe one way to do it is to cut 
off the first 5-10 minutes of temperature samples before doing the Min/Max 
calculation. It could even be a configuration option for how many minutes of 
temperature samples to ignore in the calculation so people that really want 
this info can customize it based on their own dive computer. Just my $0.02.

-Doug

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Re: Feature request - min temp and max temp options to display in dive log listing

[Robert Helling via subsurface]

Matt,

> On 14. Aug 2023, at 19:24, Matt Wilbur via subsurface 
>  wrote:
> 
> I'm not sure this is a feasible request for mobile subsurface, but on mac I 
> frequently use subsurface, and I'm also doing surveys on every dive for 
> reef.org  (I've done about 120 since may). We have to 
> report max and min temps in our surveys so they can hopefully correlate temps 
> with the critters and locations we find them in.
> 
> Would it be possible to adjust the "Temp." displayed with the dives in the 
> dive log and the "Water Temp." in the info display to show a min and max 
> water temp?  So I could just have my dive listing show me my min and max 
> temps so I don't have to mouse over the dive profile plot to read the max 
> temp on the dive?
> 
> Whether this is doable or not, thank you SO MUCH for the fantastic open 
> source dive logging app. I thought I might take a crack at adding a max temp 
> field to display since the data is all in there - but lost my steam with the 
> info "Water temp." display possibly needing to be changed too.

the problem with this is that the typical temperature sensors on dive computers 
are very slow. At the start of the dive, the dive computer probably is at the 
surface air temperature and only slowly (except for dives in mid winter 
freezing temperatures) cools down to the water temperature. Thus I would not 
expect that for the first few minutes of the dive, the recorded temperature is 
actually the ambient water temperature. So what you would be recording as the 
max temperature is probably much more related to the surface air temperature 
(which we log if the dive computer reports it).

On the other hand, the dive temperature that is shown in the dive list (you 
realise you can change the fields that are displayed there and their order) is 
the minimum temperature.

At some point, I tried plotting the temperature against depth (rather than 
against time). I was hoping to see things there like thermoclines but that did 
not work exactly for the reason of inertia of the temperature sensor.

Best
Robert



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Feature request - min temp and max temp options to display in dive log listing

[Matt Wilbur via subsurface]

Hello,

I'm not sure this is a feasible request for mobile subsurface, but on 
mac I frequently use subsurface, and I'm also doing surveys on every 
dive for reef.org (I've done about 120 since may). We have to report max 
and min temps in our surveys so they can hopefully correlate temps with 
the critters and locations we find them in.


Would it be possible to adjust the "Temp." displayed with the dives in 
the dive log and the "Water Temp." in the info display to show a min and 
max water temp?  So I could just have my dive listing show me my min and 
max temps so I don't have to mouse over the dive profile plot to read 
the max temp on the dive?


Whether this is doable or not, thank you SO MUCH for the fantastic open 
source dive logging app. I thought I might take a crack at adding a max 
temp field to display since the data is all in there - but lost my steam 
with the info "Water temp." display possibly needing to be changed too.


thank you!!

matt


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