>Along the same lines: How do you mark down the original calibration on JW
>508s and 509s ? I use a steel needle to scratch it into the brazed window
>bezel but sometimes more scratches are added during handling and then it's
>gone. Is there a marker pen that uses non-transparent non-removable ink
>and has a fine tip ?


  Yes, I am using Staedtler Lumocolor # 313 permanent ink marker refillable
(used for PCB etching  as well). The ink is removable with any acetone based
remover like nail polish remover.

 Eddy


-------------------------

This thread about "a cheaper way to erase" have been here around the list
for months. I made a search (list archives) and based on that I built my owm
eraser.
  It cost me about 20 bucks  and is safe, portable , battery operated and
nice. Moreover you can replace the regular lamp back  and use it as a
standard fluorescent lamp.

 I bought a standard battery operated fluorescent lamp  for $9.99 and then
ordered the UV D G4T5 germicidal lamp for $10.30 , added a safe enclosure
and ready to go ....12 minutes erasure time is enough for me having a pipeline.

  Safe tip : Never look into the burning lamp.