so here's a beta tester. the base current on Q2 is 100uA, the collector current result is 7.2mA when the sim is run, so the beta is 72.
the current source part of the circuit is Q1, D1, D2, R1, R2. R1 sets the current, and that current should be equal to the voltage across D2 divided by the resistance of R1. because of variations in the Vf of diode and transistor junctions, the value of R1 should be determined experimentally.
i ran it here as a sim, but with real components it works the same. even with the sim, i had to play with the value of R1 to get 100uA. with real components, a DMM from Q1 collector to ground in current mode, and without Q2 in circuit is suitable for measuring the source current. Collector current in Q2 is determined by measuring the voltage drop across R2