How to read TO-92 data sheet - DS18B20

TO-92 pinout is indeed pin 1 left, facing the flat bit.

If a top view image is given in a data sheet, do make sure it's not actually a bottom view (as it is in the image you posted - it's clearly marked BOTTOM VIEW in the data sheet).

But!

  • instead of an unclickable link to an image (which probably will die soon making your post lose relevance), it's much better to attach the image to this post.
  • instead of posting an image of a screen on which a data sheet is displayed (it's not even a screen shot!) post a link to the actual data sheet.