Triplets in triple meter?

Christo Kritzinger: The facade of the Norman and Beard organ in the Dutch Reformed Church in Burgersdorp [South Africa], built in 1913. This is the organ where I have been organist for the last 33 years.

You have probably heard that triplets in music are only created in duple meter (and duplets - in triple meter). Well, it turns out that you can play the triplets even in triple meter, IF these notes are rhythmically smaller than the beat of the measure.

For example, in 3/8 meter you can't create eighth note triplets (because that's the beat value). But you can create sixteenth note triplets very easily.

Today's piece for sight-reading is the Fugue in D minor by Wilhelm Friedemann Bach (1710-1784), J.S. Bach's eldest son which features sixteenth-note triplets in 3/8 meter. 

Here is the score (p. 7) for you. The challenge lies not only in playing triplets but also regular sixteenths which come after the triplets. Do not rush the regular sixteenths. Count out loud the beats, if you need to keep the steady pulse.