Noritsu DM-1 Densitometer

Discussion in 'Darkroom Equipment' started by Peter Rockstroh, Jul 14, 2005.

  1. Peter Rockstroh

    Peter Rockstroh Member

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    I just obtained a Noritsu DM-1 densitometer. It has a selector switch for Transmitted / Reflected Light and calibration buttons for both functions. Although it has a calibration tablet (1 white opaque dot; 1 shiny black dot), I haven´t been able to get a reading that resembles any target values, either with this tablet, paper or film. Has anyone had experience with this equipment that could give me any hints on how to proceed ?
     
  2. resummerfield

    resummerfield Subscriber

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    For what it's worth-- I once had a problem calibrating the reflection portion of an X-Rite 810. It seemed to calibrate OK, but afterward I couldn't get it to match the calibration tablet. The problem turned out to be the light bulb. It must have been making some light, but failed shortly after. A new bulb solved all problems.
     
  3. msage

    msage Member

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    Hi Peter
    I agree with Eric, the bulb may be changed. If it is the one I am thinking of, it has transmission in the main unit and reflection unit is a smaller unit atached by a cord? I may need pull ours out of stotage. Also, the calibration tablet is for reflection only, a seperate one is used to calibrate transmission.
    Michael
     
  4. L Gebhardt

    L Gebhardt Subscriber

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    Peter, I have used the same unit.

    To calibrate:
    1) put the white dot under and press the zero button on the arm.
    2) Open the cover on the side and adjust the R-Level until the amount matches the marking on the calibration strip.
    3) Then put the black dot under and adjust the reflected gain using the R-Cal knob on the side.

    If that doesn't work you probably need a new bulb as stated above.
     
  5. Peter Rockstroh

    Peter Rockstroh Member

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    Thanks for all your comments. I hope I can get a replacement bulb, if its not one of these esotheric spare parts. I assume that any further calibration efforts are futile if the light source isn`t trustworthy.