Well, you bought what was a very nice color analyzer in its day, not a densitometer.

You can calibrate it to do B&W, and those modules can be configured as presets for your favorite color or B&W tones, but it won't give you standard density readings.

One caveat that usually applies to analyzers of that vintage (I have a less fancy one)--don't turn it on with the roomlights on or you can damage the sensor. It should only be turned on in the darkroom under enlarger light.

If it doesn't come with a manual, you may be able to get a photocopy from Beseler (or whoever owns them now) or from www.craigcamera.com.

If you really have no use for such a thing, Columbus Camera should be able to nullify the sale, since they made an error in the listing, and I've had good dealings with them in the past. On the other hand, it's not a bad color analyzer for $60.