From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-x112e.google.com (mail-yw1-x112e.google.com [IPv6:2607:f8b0:4864:20::112e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 666C23CB38; Sat, 18 Mar 2023 15:57:30 -0400 (EDT) Received: by mail-yw1-x112e.google.com with SMTP id 00721157ae682-5418c2b8ef2so156860447b3.5; Sat, 18 Mar 2023 12:57:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679169450; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=Bppl7qnKu5qTOzPzoJc+fWQchfBDSGsPun05JCrAuAg=; b=m8kLU6mBvs//LTLlRY5Kjv9I/DYkxBDOHtfdW2Ws9n/N0YuxdqSBeZVrfHG0K62B7X 0YZLh6X8ygXcnagWcNP+eXAgN2fzfW18H/2UiJ0gSnbcgSxkhDcAn93jDJji59k8N0M+ KBmn8jCDiVzbFBw5rdDUHKWXenkPp25nQTP7OpVKdZGMR+vBI5JklmmjqpHNpj3x5C41 9vZ4Mz1h34XvMxhwrHuYghLIz6xiClVl4UWQrohRXY+NHuoNiuIMDI4xo5ob+Wx7o++G lO7dmzzbBYGyvk6GdWMQbeLJSLwhq+ysKBAJfcwkOBe+rDyvOdBhz0yQ3k7qVL5JozbX msDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679169450; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Bppl7qnKu5qTOzPzoJc+fWQchfBDSGsPun05JCrAuAg=; b=Ndw53nzoBZNW4gD6jRZAvPf5KrNdOSDfY3qfoZUsk1AlHmvczGGjmj7esyTUU5/x/G jMhECwoJHb9OaxHFK09H3MGQBR1aSaVOfYaW+p2N89XoGIvA+XMURSNNfXl97l8qar/c 9ba8aECeDTFdrItotkuPogAKojl0hlwb9UiJ/I1wUfupK3mZ65mZ+lAAc/U0MPsU6WoV 2mIDsR8miHztGdNucfrgkniKx+73eMQQas7rRaZSgn71kWGdYPScVJLP5AEi3yQR5t1E 5CJ3YAdymXNL5g9Da/xAohkWraMbmU//SWDkR7E8RauE61wPl979kyYDQHBj5IFMLutW VIrA== X-Gm-Message-State: AO0yUKVTfr8kJrCw4UhZLGs1Q7eDWF1Qw+IRyEWI7Fw2X0JIyKD5W9lA t1h3c8V8fVp52Z4qKAthyucw2KkcFNr0Q7fpqaU= X-Google-Smtp-Source: AK7set/8ntz2utC3iQ5qG7x3mNxciQx3M+T+DLLrco0JirSFEGZPY9tRAXZHXXjxskT5NZPgbU6r0CnEstmoh/6qmtc= X-Received: by 2002:a05:690c:731:b0:544:8405:e1f9 with SMTP id bt17-20020a05690c073100b005448405e1f9mr6947375ywb.1.1679169449657; Sat, 18 Mar 2023 12:57:29 -0700 (PDT) MIME-Version: 1.0 References: <1672786712.106922180@apps.rackspace.com> <77CCAD19-07E0-4F9E-88C1-D207CF7BF376@cable.comcast.com> <83ffc0dad19e3343e49271889369cefc@rjmcmahon.com> <3CD0B9E6-0B2A-4A70-8F53-ED0822DF77A6@gmx.de> <13DE6E53-665F-4C20-BBE2-70E685421E9D@gmx.de> <22C819FA-DDD7-4B9B-8C09-8008D4273287@gmx.de> <5e7fac51071bdbb20837e72e7eedfc7c@rjmcmahon.com> <3f45d2a0b6e46d7b2775fb801e805f93@rjmcmahon.com> <70F71290-C6CB-4D19-8A88-F0F17C0BDDA2@gmx.de> <5e0cd693c4749d128dbb48d6c1129071@rjmcmahon.com> <2ab2983d-6beb-49cb-8c35-e481cbfdc7a3@Spark> <8F56CCA3-61C4-475F-975D-99D851C6A7CF@gmx.de> <1d6c10c9a692bb3f2869fb1b40fa449a@rjmcmahon.com> <005d1e7e3e1d19bce308436e46a3ec5e@rjmcmahon.com> In-Reply-To: From: dan Date: Sat, 18 Mar 2023 13:57:18 -0600 Message-ID: To: rjmcmahon Cc: Bruce Perens , Dave Taht via Starlink , Rpm , Sebastian Moeller , bloat , libreqos Content-Type: multipart/alternative; boundary="00000000000090886605f7321af1" Subject: Re: [Rpm] [LibreQoS] [Starlink] On FiWi X-BeenThere: rpm@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: revolutions per minute - a new metric for measuring responsiveness List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 18 Mar 2023 19:57:30 -0000 --00000000000090886605f7321af1 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, Mar 18, 2023 at 12:18 PM rjmcmahon via LibreQoS < libreqos@lists.bufferbloat.net> wrote: > >> I'm curious as to why the detectors have to be replaced every 10 > >> years. > > > > Dust, grease from cooking oil vapors, insects, mold, etc. accumulate, > > and it's so expensive to clean those little sensors, and there is so > > much liability associated with them, that it's cheaper to replace the > > head every 10 years. Electrolytic capacitors have a limited lifetime > > and that is also a good reason to replace the device. > > > > The basic sensor architecture is photoelectric, the older ones used an > > americium pelllet that detected gas ionization which was changed by > > the presence of smoke. The half-life on the americium ones is at least > > 400 years (there is more than one isotope, that's the shortest-life > > one). > > Thanks for this. That makes sense. I do think the FiWi transceivers & > sensors need to be pluggable & detect failures, particularly early on > due to infant mortality. > > "Infant mortality is a special equipment failure mode that shows the > probability of failure being highest when the equipment is first > started, but reduces as time goes on. Eventually, the probability of > failure levels off after time." > > > https://www.upkeep.com/blog/infant-mortality-equipment-failure#:~:text=3D= Infant%20mortality%20is%20a%20special,failure%20levels%20off%20after%20time > . > > Also curious about thermal imaging inside a building - what sensor tech > to use and at what cost? The Bronx fire occurred because poor people in > public housing don't have access to electric heat pumps & used a space > heater instead. It's very sad we as a society do this, i.e. make sure > rich people can drive Teslas with heat pumps but only provide the worst > type of heating to children from families that aren't so fortunate. > > > https://www.cnn.com/2022/01/10/us/nyc-bronx-apartment-fire-monday/index.h= tml > > "A malfunctioning electric space heater in a bedroom was the source of > an apartment building fire Sunday in the Bronx that killed 17 people, > including 8 children, making it one of the worst fires in the city=E2=80= =99s > history, New York Mayor Eric Adams said Monday." > > Bob > _______________________________________________ > LibreQoS mailing list > LibreQoS@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/libreqos > All of the states use cases are already handled by inexpensive lorawan sensors and are already covered by multiple lorawan networks in NYC and most urban centers in the US. There is no need for a new infrastructure, it=E2=80=99s already there. Not to mention NBIoT/catm radios. This is all just general cheapness and lack of liability keeping these out of widespread deployment. It=E2=80=99s not lack of tech on the market today= . --00000000000090886605f7321af1 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Sat, Mar 18, 2023 at 12:18 PM rjmcmahon via LibreQoS <= ;libreqos@lists.bufferblo= at.net> wrote:
>> I'm curious as= to why the detectors have to be replaced every 10
>> years.
>
> Dust, grease from cooking oil vapors, insects, mold, etc. accumulate,<= br> > and it's so expensive to clean those little sensors, and there is = so
> much liability associated with them, that it's cheaper to replace = the
> head every 10 years. Electrolytic capacitors have a limited lifetime > and that is also a good reason to replace the device.
>
> The basic sensor architecture is photoelectric, the older ones used an=
> americium pelllet that detected gas ionization which was changed by > the presence of smoke. The half-life on the americium ones is at least=
> 400 years (there is more than one isotope, that's the shortest-lif= e
> one).

Thanks for this. That makes sense. I do think the FiWi transceivers & <= br> sensors need to be pluggable & detect failures, particularly early on <= br> due to infant mortality.

"Infant mortality is a special equipment failure mode that shows the <= br> probability of failure being highest when the equipment is first
started, but reduces as time goes on. Eventually, the probability of
failure levels off after time."

https://www.upkeep.com/blog= /infant-mortality-equipment-failure#:~:text=3DInfant%20mortality%20is%20a%2= 0special,failure%20levels%20off%20after%20time.

Also curious about thermal imaging inside a building - what sensor tech to use and at what cost? The Bronx fire occurred because poor people in public housing don't have access to electric heat pumps & used a sp= ace
heater instead. It's very sad we as a society do this, i.e. make sure <= br> rich people can drive Teslas with heat pumps but only provide the worst type of heating to children from families that aren't so fortunate.

https://www.cnn.com/2022= /01/10/us/nyc-bronx-apartment-fire-monday/index.html

"A malfunctioning electric space heater in a bedroom was the source of=
an apartment building fire Sunday in the Bronx that killed 17 people,
including 8 children, making it one of the worst fires in the city=E2=80=99= s
history, New York Mayor Eric Adams said Monday."

Bob
_______________________________________________
LibreQoS mailing list
LibreQo= S@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/libreqos
All of the states use cases are = already handled by inexpensive lorawan sensors and are already covered by m= ultiple lorawan networks in NYC and most urban centers in the US.=C2=A0 The= re is no need for a new infrastructure, it=E2=80=99s already there.=C2=A0 N= ot to mention NBIoT/catm radios.

This is all just general cheapness and lack of liability keeping = these out of widespread deployment. It=E2=80=99s not lack of tech on the ma= rket today.
--00000000000090886605f7321af1--