I have an Eps 16 Plus with about 19 seconds of sample time. What would I need to increase the sample time????? And what would I need to load more instruments???? Any info is gratly appreciated....

I believe the plus maxes out at 4megs. You can reduce the sample rate which will give you a longer sample but you'll sacrifice sound quality.

How do I find out by how much the memory has been expanded?

I sold my EPS a long time ago so I don't remember where, but there should be a soft page that list the details of your EPS including how much memory you have installed. However, with 4megs, a stereo sample at 48 KHz should yeild about 20 seconds of sample time. Since you sataed that you are getting around 19 seconds, and if that is in stereo, you may already be at the 4meg max.
I didn't think of this earlier but in addition to lowering the sample rate, you can almost double your sample time by sampling in mono rather than stereo.
Sampling things with high frequency content (cymbals, woodwinds, etc.) should be sampled at higher rates but do not necessarily need to be sampled in stereo. Bases, on ther other hand usually don't contain high frequencies and can be sampled at a slightly lower rate. So, by keeping the frequencies of what you are sampling in mind, as well as the need for a stereo image, will help you to conserve memory.
In my opinion, the memory limit was the only drawback of the EPS, otherwise it's a great sampler with killer effects.

Thanks Buinu, the info was very useful!!!!!

since the EPS16+ cant sample in stereo, i would guess yours has only 2 MB installed.

that would mean, you could double your sampling time by buying the memory expansion (hard to find these days, but syntaur or rubber chicken may have some).

be warned that the price is going to be kind of high - were talking about really rare parts for an old sampler here (the eps is from 1990 or so)