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Thread: PM2 and Base Unit Temperature Offsets

  1. #1
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    PM2 and Base Unit Temperature Offsets

    Why is the temperature offset on the base module -3 and on the PM2 module it is at -9?

    If you are using the same temperature probe, why would it be factory set to different values?

    I am in the process of calibrating the salinity probe. I switched the temp probe from the base unit temp input to the tmpx4 input on the PM2.

    Now I am confused on what to put the offset at.

  2. #2
    Master Control Freak RussM's Avatar
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    Quote Originally Posted by Tuffloud1 View Post
    Why is the temperature offset on the base module -3 and on the PM2 module it is at -9?

    If you are using the same temperature probe, why would it be factory set to different values?

    I am in the process of calibrating the salinity probe. I switched the temp probe from the base unit temp input to the tmpx4 input on the PM2.

    Now I am confused on what to put the offset at.
    My hunch is that there is slightly different circuitry in the PM2 vs. in the Apex, so there is a small difference in the default offset (calibration) values. Don't worry about the temp offset itself... what matters is that it reads correctly.
    Please do not send me PMs with technical questions or requesting assistance - use the forums for Apex help. PM me ONLY if the matter is of a private or personal nature. Thanks.

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    Ya but the thing is, the base was reading 78.1 and when I unplugged the temp probe and immediately plugged it into the PM2, it read 78.7 on the tmpx4.

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    Master Control Freak RussM's Avatar
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    Quote Originally Posted by Tuffloud1 View Post
    Ya but the thing is, the base was reading 78.1 and when I unplugged the temp probe and immediately plugged it into the PM2, it read 78.7 on the tmpx4.
    Then calibrate it to be 78.1, if you believe that to be the correct temperature.
    Please do not send me PMs with technical questions or requesting assistance - use the forums for Apex help. PM me ONLY if the matter is of a private or personal nature. Thanks.

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    Thanks Russ, I appreciate your help on here.

    - - - Updated - - -

    Oh ya, last question. If I calibrate the unit, can I go back and erase that manual calibration and bring it back to factory default?

  6. #6
    Master Control Freak RussM's Avatar
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    Quote Originally Posted by Tuffloud1 View Post
    Thanks Russ, I appreciate your help on here.

    - - - Updated - - -

    Oh ya, last question. If I calibrate the unit, can I go back and erase that manual calibration and bring it back to factory default?
    No, not directly. Bit you can just recalibrate it, entering a suitable temp value so that the offset goes back to -3 (or -9). Each integer value in the offset equates to 0.1 degrees of change in temp.
    Please do not send me PMs with technical questions or requesting assistance - use the forums for Apex help. PM me ONLY if the matter is of a private or personal nature. Thanks.

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    Quote Originally Posted by RussM View Post
    Each integer value in the offset equates to 0.1 degrees of change in temp.
    So I have two Temp probes:

    Temp_T is plugged into the base unit and has a factory offset of -3 and that probe is in the tank and reads 75.0

    Temp_S is plugged into the PM1 unit and has a factory offset of -9 and that probe is in the Sump and reads 76.5

    So my temp probe in the sump reads on average of 1.5 degrees higher then my tank temp probe, and I have checked with two different thermometers and the tank and the sump are not 1.5 degrees different.

    Is this how I would calculate it? 1.5 deg = 10.5 integers? (I was/am bad at math)......

    What would I want my offset to be on my Temp_S?.........(-9 + -10.5 =19.5) or (-9 + 10.5 = 1.5)

    Thanks Jon

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    Quote Originally Posted by jonmos75 View Post
    So I have two Temp probes:

    Temp_T is plugged into the base unit and has a factory offset of -3 and that probe is in the tank and reads 75.0

    Temp_S is plugged into the PM1 unit and has a factory offset of -9 and that probe is in the Sump and reads 76.5

    So my temp probe in the sump reads on average of 1.5 degrees higher then my tank temp probe, and I have checked with two different thermometers and the tank and the sump are not 1.5 degrees different.

    Is this how I would calculate it? 1.5 deg = 10.5 integers? (I was/am bad at math)......

    What would I want my offset to be on my Temp_S?.........(-9 + -10.5 =19.5) or (-9 + 10.5 = 1.5)

    Thanks Jon
    Does anyone have any input on which way I should adjust my temp probe on the PM1 to match my temp probe on the Base unit?

    Thanks Jon

  9. #9
    Master Control Freak RussM's Avatar
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    Quote Originally Posted by jonmos75 View Post
    Does anyone have any input on which way I should adjust my temp probe on the PM1 to match my temp probe on the Base unit?
    Disregard the offsets. Just calibrate the PM1 temp probe to the desired reading.

    1. Note the current base unit temp probe reading
    2. On the Probe/Input Setup page, select your PM1 temp probe.
    3. Click Calibrate
    4. Enter the temp value noted in step 1
    5. Click Finish
    6. Click Update Settings
    Please do not send me PMs with technical questions or requesting assistance - use the forums for Apex help. PM me ONLY if the matter is of a private or personal nature. Thanks.

  10. #10
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    Russ,

    Thanks again for you info and support you give to us.

    Jon

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