I've lost on average one L thermocouple per year on two separate 4010
EA's.  That is running at 1020C, and using standby whenever the machine
is not in use.

The last failure took out my oven also and now I have the new design
bigger (3mm) thermocouples L and R on one system.  So far so good since
last fall.

 
Benjamin Harlow
Manager, Stable Isotope Core Laboratory
Washington State University
School of Biological Sciences
G-81 Eastlick
Pullman, WA  99164-4236
 
Office:  509-335-6161
Lab:     509-335-6154
Fax:     509-335-3184
 
Laboratory for Biotechnology and Bioanalysis (LBB2) Stable Isotope Core
http://www.isotopes.wsu.edu
 
 

-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On
Behalf Of Fname Lname
Sent: Monday, August 10, 2009 6:44 AM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] EA Left Thermocouple

I have had this happen as well with the easy fix of possibly: 1)
grounding insufficient which Jason wrote about (I would like to see
the .pdf on the fix please Jason).

or 2) Check your thermocouple placement.  I have had the thermocouple
slide down a bit (2-3cm) so the readings are fluctuating and therefore
in a "not ready" state .  Easy fix of adjusting the thermocouple back to
correct placement resulting in steady readings.

On the thermocouple subject, two questions:

1) What is the average lifetime of the thermocouples, especially the
left?

2) Does the lifetime shorten if you leave the thermocouple at 1050 C or
if you place the instrument in stdby mode decreasing the thermocouple
temp?

Anne Cotter

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anne M. Cotter
U.S. Environmental Protection Agency
Mid-Continent Ecology Division
6201 Congdon Blvd
Duluth, MN 55804
218-529-5183
fax 218-529-5003
[log in to unmask]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


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  |Sandra Ellis <[log in to unmask]>
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>-----------------------------------------------------------------------
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  |08/07/2009 01:29 PM
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  |[ISOGEOCHEM] EA Left Thermocouple
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  |Stable Isotope Geochemistry <[log in to unmask]>
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Isogeochemers,

Yesterday morning, our Costech 4010 Elemental Analyzer had the error
message "Left Thermocouple KO".  We changed the thermocouple and brought
the temperature up slowly to 1050 C, which is the normal temperature at
which we run analysis.  We let the system sit and bake over night.  This
morning, the temperature was at 1050 C and the light was green and the
display indicated the system was "ready".  However, when I started to
run standards today the LED indicator light flashed red and the display
changed to "Not Ready" the temperature began to fluctuate between 1040 C
and 1055 C.  I was wondering what would cause this problem and any
possible solutions.  Any help would be greatly apprecaited.

Thank you,

Sandra Ellis
Laboratory Manager
Chemical Tracers Laboratory
Great Lakes Institute for Environmental Research
University of Windsor
401 Sunset Ave
Windsor, Ontario
N9B 3P4
phone : 519-253-3000 ext. 4851
fax: 519-971-3616