What colour is ‘Cherry Red’?

[Neil WyattModerator @neilwyatt]

Posted by SillyOldDuffer on 07/12/2017 11:01:14:

Only by reading the World Museum of Carrots website ('Discover the Power of Carrots' ) did I learn that Carrots and Parsnip were once thought to be the same vegetable.

After reading that website I was left wondering if carrots have always been orange…

Neil

 

Edited By Neil Wyatt on 07/12/2017 16:22:31

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Harry Wilkes on 07/12/2017 15:44:28:

. A £15 multimeter from Chester () comes with a type K thermocouple that will indicate the temperature.

Rod

Would this be the MY 64A multimeter your referring to ?

That's the one.

Rod

[duncan webster 1Participant @duncanwebster1]

There's a colour chart in Tubal Cain's book Hardening Tempering and Heat Treatmaent. Not much use if you're colour blind though. However a friend of mine once had a job wiring up the old Stowger telephone thingies even tho he was red/green colour blind. Don't ask me how!

[Andrew TinsleyParticipant @andrewtinsley63637]

There seem to be a lot of infra red thermometers on the market these days. People use them for measuring the head temperatures of model IC engines for example. I don't know what range they cover, but it sounds as if they could measure the black body locus curve quite accurately. That is assuming they go to a higher enough temperature.

I am now able to follow the various "colours" that one sees with pretty good accuracy, but that is only because I have had plenty of practice. Not very helpful to a beginner!

One needs to view in very subdued lighting, otherwise I get caught out! So be warned!

Andrew.

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Andrew Tinsley on 07/12/2017 18:23:37:One needs to view in very subdued lighting, otherwise I get caught out! So be warned!

It depends what you are used to. My man cave has no natural lighting so it's flourescent or nothing but I don't have problems being accustomed to it for the last 12 years.

There was an interesting programme on BBC Four last night on quantum theory that explained why the colour doesn't change above white heat.

Russell

[Andrew TinsleyParticipant @andrewtinsley63637]

The black body locus is nearly flat at white heat, hence no colour change.

Andrew.

[larry PhelanParticipant @larryphelan54019]

Dave,have a word with your local blacksmith ! These guys have it down to a fine art.

[SillyOldDufferModerator @sillyoldduffer]

Posted by larry Phelan on 08/12/2017 11:14:56:

Dave,have a word with your local blacksmith ! …

My village had 3 forges before the Great War. Now the nearest that advertises is 50km as the crow flies. More like 100km by bendy B-roads. Slightly odd as there are plenty of horses round here; I must ask one of the horsey set where they get their shoes done. Perhaps the first rule of Blacksmith Club is that you don't talk about Blacksmith Club!

Dave

[HevansccParticipant @hevanscc]

I recently quench hardened some gear cutters and used the muffle furnace at work to heat them, so the temperature was well controlled.

I would say that the boiled carrots in subdued light colour is a good comparison – a nice soft orangey glow. It was certainly nothing like any cherries that I have ever seen!

Hywel

[Michael GilliganParticipant @michaelgilligan61133]

The chart on this page looks pretty reasonable:

**LINK**

http://www.canadianknifemaker.ca/index.php?threads/heat-treating.1459/

[ with the usual caveat that display screen performance varies widely !! ]

MichaelG.

[Author]

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