Access Database Query Question

I am developing a database for a process for which we take samples at multiple times. So I have multiple processes (test1, test2, etc), with multiple samples for each test (-01,-02,-03)

I have a table of the form:

TEST ID........DATASET ID...........TIME.........OTHER DATA
test1.............test1-01...............4
test1.............test1-02...............5
test1.............test1-03...............8
test2.............test2-01...............2
test2.............test2-02...............4
test2.............test2-03...............9


My initial "raw data" table is of this form, (with multiple "other data" fields containing data of the samples taken at the particular time)

With all this raw data I need to calculate values. However, some of these values depend on the change in time between samples taken. For example, I need an automated way of calculating the time elapsed between dataset "test1-01" and dataset "test1-02" (4.6 hours).

I need to then be able to pull this value and use it in other calculations (a seperate query perhaps?).

The problem is I am having to recreate many calculations which were previously done in a spreadsheet. I have already found a way to mimic "absolute references" with multiple queries for the calculation in access. However, I am stuck on how to recreate this calculation.

THANKS IN ADVANCE!

You can then always calculate the time at runtime in ur program. ?