[NTG-context] dimen 100.0pt not 100.0pt?

The I do not understand. I am testing if a dimension set can be checked against the expected value. It looks like 100.0pt is not really 100.0pt. Why? And how can I do this test properly with true as result? \scratchdimen=100pt\relax \iftok{\the\scratchdimen}{100.0pt}true\else false\fi  printing \the\scratchdimen results in 100.0pt while \meaning\scratchdimen results in: constant dimension 100.0pt yours sincerely dr. Hans van der Meer