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Date: 10 Feb 2007 11:36:10
From: SnizzbutsDad
Subject: Fun with a fluke infra-red thermometer
I've just bought a fluke 63 infra-red thermometer off ebay. After
driving the family mad by measuring the temperature of everything in
sight, I turned my attention to my gaggia italcrem espresso machine.
I've been wondering just how hot the large chrome group head actually
is, and whether high or low use of the machine makes a difference to
the temperature of the portafilter. The fluke has a laser on it, and
has about a 1inch disk of measurement at 10 inches, so it's fine on my
espresso machine (tolerance is about 2 degrees at 100 degrees C I
think).

Well the group head itself is at about 60 degrees C

The portafilter is about 80 degrees C

After a shot of espresso, if I whip the portfafilter straight off the
group and measure the temperature of the coffee puck, it's about 86
degrees C

I also noticed that the temperature of the portafilter drops very
quickly, probably a degree every few seconds once removed from the
group head.

The result of my investigation:

1. I probably need to service the group head and maybe it needs
descaling, looks like it's running too cold.

2. I'll run hot water through the group head before drying and then
loading the portafilter with coffee, and I'll load and tamp quickly,
and then do the shot.

3. The group head seems to be quite stable in temperature if the
machine is idle or in use.

4. My fluke 63 will become quite a useful part of my coffee regime.





 
Date: 12 Feb 2007 02:48:10
From: SnizzbutsDad
Subject: Re: Fun with a fluke infra-red thermometer
On Feb 11, 4:56 pm, Steve Ackman <s...@SNIP-THIS.twoloonscoffee.com >
wrote:
> In <5387leF1rgs3...@mid.individual.net>, on Sun, 11 Feb 2007 09:58:03
>
> -0000, Bertie Doe wrote:
> > "Barry Jarrett" wrote
> >> are you accounting for the difference in emissivity between materials?
>
> > I read on Wilkpd or somewhere, that you can eliminate emissivity errors,
> > with the use of 2" black electrician's tape (it's the tape that's black).
> > Stick a square on the target metal etc. ok there's going to be some glue goo
> > residue to clean up, but it improves the figs.
> > Bertie
>
> I highly doubt that black electrical tape has the
> same emissivity that IR thermometers are calibrated
> against. Generally they tend to go against something
> "middle of the road."
>
> Using tape like that doesn't necessarily improve
> the accuracy of each reading, but it does improve your
> readings relative to each other.
>
> Good tip... though on reflection, it might be tough
> to stick electrical tape to a puck! ;-)

I feel a bit foolish here. It didn't say in the fluke literature
anything about emissivity calibration or anything like that. I did try
putting some black newspaper on the group head, and the reading went
up from 60 to 67. I tried holding my milk thermometer against the
group head with an oven glove and it went up to 75 degrees C. I feel
like an idiot. Ah well, I'll have to save up for a fluke 51 and type k
bead thingy

thanks again

Paul



  
Date: 12 Feb 2007 17:08:33
From: bernie
Subject: Re: Fun with a fluke infra-red thermometer
SnizzbutsDad wrote:

> I feel a bit foolish here. It didn't say in the fluke literature
> anything about emissivity calibration or anything like that. I did try
> putting some black newspaper on the group head, and the reading went
> up from 60 to 67. I tried holding my milk thermometer against the
> group head with an oven glove and it went up to 75 degrees C. I feel
> like an idiot. Ah well, I'll have to save up for a fluke 51 and type k
> bead thingy
>
> thanks again
>
> Paul
>

If it would help you to feel less foolish you are welcome to send the
unit to me.=) I'd be more than happy to have another toy,uh, I mean tool.
Bernie (hold still while I bounce a laser off yer noggin)D


 
Date: 10 Feb 2007 13:59:28
From: daveb
Subject: Re: Fun with a fluke infra-red thermometer
I compliment your sincere efforts and study on this.

but I owned a 63 IR thermometer and found it to be entirely useless
around espresso machines.

the sensor has to be immersed in the affected liquid.

[due to the differences in IR emissivity as Barry mentions.]

Dave

215


On Feb 10, 2:36 pm, "SnizzbutsDad" <p...@rockfaith.net > wrote:
> I've just bought a fluke 63 infra-red thermometer off ebay. After
> driving the family mad by measuring the temperature of everything in
> sight, I turned my attention to my gaggia italcrem espresso machine.
> I've been wondering just how hot the large chrome group head actually
> is, and whether high or low use of the machine makes a difference to
> the temperature of the portafilter. The fluke has a laser on it, and
> has about a 1inch disk of measurement at 10 inches, so it's fine on my
> espresso machine (tolerance is about 2 degrees at 100 degrees C I
> think).
>
> Well the group head itself is at about 60 degrees C
>
> The portafilter is about 80 degrees C
>
> After a shot of espresso, if I whip the portfafilter straight off the
> group and measure the temperature of the coffee puck, it's about 86
> degrees C
>
> I also noticed that the temperature of the portafilter drops very
> quickly, probably a degree every few seconds once removed from the
> group head.
>
> The result of my investigation:
>
> 1. I probably need to service the group head and maybe it needs
> descaling, looks like it's running too cold.
>
> 2. I'll run hot water through the group head before drying and then
> loading the portafilter with coffee, and I'll load and tamp quickly,
> and then do the shot.
>
> 3. The group head seems to be quite stable in temperature if the
> machine is idle or in use.
>
> 4. My fluke 63 will become quite a useful part of my coffee regime.




 
Date: 10 Feb 2007 19:42:24
From: Barry Jarrett
Subject: Re: Fun with a fluke infra-red thermometer
On 10 Feb 2007 11:36:10 -0800, "SnizzbutsDad" <paul@rockfaith.net >
wrote:

>
>Well the group head itself is at about 60 degrees C
>
>The portafilter is about 80 degrees C
>
>After a shot of espresso, if I whip the portfafilter straight off the
>group and measure the temperature of the coffee puck, it's about 86
>degrees C
>

are you accounting for the difference in emissivity between materials?



  
Date: 11 Feb 2007 09:58:03
From: Bertie Doe
Subject: Re: Fun with a fluke infra-red thermometer
"daveb" <davebobblane@gmail.com > wrote in message
news:1171144768.333934.247300@a75g2000cwd.googlegroups.com...
>I compliment your sincere efforts and study on this.
>
> but I owned a 63 IR thermometer and found it to be entirely useless
> around espresso machines.
>
> the sensor has to be immersed in the affected liquid.
>
> [due to the differences in IR emissivity as Barry mentions.]

"Barry Jarrett" wrote in message
> On 10 Feb 2007 11:36:10 -0800, "SnizzbutsDad" <paul@rockfaith.net>
> wrote:
>
> >
> >Well the group head itself is at about 60 degrees C
> >
> >The portafilter is about 80 degrees C
> >
> >After a shot of espresso, if I whip the portfafilter straight off the
> >group and measure the temperature of the coffee puck, it's about 86
> >degrees C
> >
>
> are you accounting for the difference in emissivity between materials?
>
I read on Wilkpd or somewhere, that you can eliminate emissivity errors,
with the use of 2" black electrician's tape (it's the tape that's black).
Stick a square on the target metal etc. ok there's going to be some glue goo
residue to clean up, but it improves the figs.
Bertie




   
Date: 11 Feb 2007 11:56:38
From: Steve Ackman
Subject: Re: Fun with a fluke infra-red thermometer
In <5387leF1rgs3uU1@mid.individual.net >, on Sun, 11 Feb 2007 09:58:03
-0000, Bertie Doe wrote:

> "Barry Jarrett" wrote

>> are you accounting for the difference in emissivity between materials?
>>
> I read on Wilkpd or somewhere, that you can eliminate emissivity errors,
> with the use of 2" black electrician's tape (it's the tape that's black).
> Stick a square on the target metal etc. ok there's going to be some glue goo
> residue to clean up, but it improves the figs.
> Bertie

I highly doubt that black electrical tape has the
same emissivity that IR thermometers are calibrated
against. Generally they tend to go against something
"middle of the road."

Using tape like that doesn't necessarily improve
the accuracy of each reading, but it does improve your
readings relative to each other.

Good tip... though on reflection, it might be tough
to stick electrical tape to a puck! ;-)