Motherboard where? Marilyn

From: Stable Isotope Geochemistry <[log in to unmask]> on behalf of Wei Huang <[log in to unmask]>
Reply-To: Stable Isotope Geochemistry <[log in to unmask]>
Date: Monday, July 30, 2018 at 10:01 AM
To: <[log in to unmask]>
Subject: Re: [ISOGEOCHEM] Isolink HTC oven couldn't reach the desired temperature

Hi all,

The problem was solved by replacing the motherboard. Thank you for all the suggestions and information!

Wei

On Tue, Jul 17, 2018 at 8:43 AM, Stefan Merseburger <[log in to unmask]> wrote:

Hello Wei,

it's probably a confusion. The transformer in the HTC does not increase the voltage but the internal amperage. Usually if ~225V or 230V doesn't matter. We have the predecessor of the IsoLink HTC (Flash 2000 HTC Plus, or so) and after a few month, it was necessary to increase the current intensity (following the described procedure in the manual: unscrew backside and set the cable of the associated transformer one number higher). Nevertheless, with this problem, we could reach easily above 1400°C and then the temperature was slowly fluctuating below 1450°C. Your description sounds different to me.

In addition, you could have another software related problem (we also suffered): The ThermoFisher Software IsoDat had a wrong max. Temperature set somewhere deeply hidden in its settings for the HTC side. To solve that we had to install the old "Eager Experience" software (for operating the HTC/EA without mass spectrometer), that overrides the faulty setting with the correct one. Our max. point was 1100°C, maybe yours is now 1200°C? Then our "Pyrolysis Mode" got it's right maximum temperature back.
I hope it helps.

Good luck,
Stefan



Am 16.07.2018 um 22:32 schrieb Wei Huang:

Thank you for all online/offline helps!

The new ovens came with new thermocouples (built in). So, it shouldn't be thermocouple issue. This Isolink HTC oven doesn't have the transformer to increase voltage as TCEA oven does. Our current inlet voltage is ~225V rather than 230V. I am thinking if it is possible to add a transformer to this HTC oven. I have scheduled an electrician and will see what is his suggestion. I will keep updating here.

Wei

On Mon, Jul 16, 2018 at 4:35 AM, Kolar, Allison (IMK) <[log in to unmask] <mailto:[log in to unmask]>> wrote:

    It would be a good idea to check the thermocouple as well. I agree.
    I had the same issue years ago with our Flash EA 1112 and it was a
    faulty thermocouple. (The furnace was changed some time afterward –
    but this was due to other circumstances – the temperature showed the
    correct reading, but samples were not combusting and after removing
    the front of the instrument, it was apparent the furnace was not
    heating up sufficiently.)____

    __ __

    Good luck____

    __ __

    *From:*Stable Isotope Geochemistry <[log in to unmask]
    <mailto:[log in to unmask]u>> *On Behalf Of *mwolhowe
    *Sent:* Friday, July 13, 2018 8:13 PM
    *To:* [log in to unmask] <mailto:[log in to unmask]U>
    *Subject:* Re: [ISOGEOCHEM] Isolink HTC oven couldn't reach the
    desired temperature____

    __ __

    It sounds like a problem with the power supply to the furnace itself
    to me. I don't know about HTC on the newer isolink, but the the
    older GC-TC interface had a big external power supply that was
    necessary to get the TC furnace up that high - I forget the exact
    details of this because I last did it so long ago, they occasionally
    need to be opened up and have a wire 'tapped into' a different
    position on a... transformer I believe it was? I had THOUGHT that
    was due to changing resistance in the furnace over time, but perhaps
    I was misinformed? The one time I did this, it was because of the
    same symptoms you describe (thought we didn't have multiple furnaces
    to test on). Does anyone else have more recent experience having to
    do this?____

    In any event, I'd take a look into the health of the power supply.
    There should be some sort of solid state relay that switches current
    to the heater on and off at the command of the temp controller, I
    know those things can wear over time and have problems switching on
    and off at the desired frequency (we just had one in a muffle
    furnace die and melt a bunch of glassware).____

    Alternately, have you tried swapping the thermocouple or checking
    with an external one?____

    __ __

    On Fri, Jul 13, 2018 at 7:25 AM, Wei Huang <[log in to unmask]
    <mailto:[log in to unmask]m>> wrote:____

        Dear all,____

        __ __

        Our HTC oven on Thermo Isolink couldn't reach the desired
        temperature - 1400 degree C. It could be heated up to ~ 1200
        degree and stayed at 1200 with setting 1400 degree. Everything
        looked normal. There was not any error message. The first
        thought was the oven failed. So, we tested another two new HTC
        ovens. The first one stayed at ~1200 degree with setting at
        1400, and the second stayed at ~1000 degree. It is less possible
        all three ovens are bad. Anybody has idea about it? Thank you
        very much in advance!____

        __ __

        ____

        Wei Huang, Ph.D.____

        ____

        Stable Isotope Lab Manager____

        Lamont-Doherty Earth Observatory of Columbia University____

        61 Route 9W
        <https://maps.google.com/?q=61+Route+9W+%0D%0APalisades,+NY+10964&entry=gmail&source=g>
        Palisades, NY 10964
        Lab: 845-365-8143 <tel:845-365-8306>
        [log in to unmask] <mailto:[log in to unmask]>____

        __ __

        __ __

    __ __

--

Stefan Merseburger
Tel.: +49 721 608-41678
Karlsruher Institut für Technologie
Institut für Geographie und Geoökologie
Reinhard-Baumeister-Platz 1
76131 Karlsruhe
Germany