Noritsu DM-1 Densitometer

[Peter Rockstroh]

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 ?

 

[resummerfield]

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.

 

[msage]

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

 

[L Gebhardt]

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.

 

[Peter Rockstroh]

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.