As the title says, this is a preliminary test of the first version of the multimeter. Before the test, I basically calibrated it using my Fluke 101 as a reference. The results of the test are as follows:

2.5V
Error: 0.569, Coeff of Var: 0.0102

5V
Error: 0.2342, Coeff of Var: 0.001

7.5V
Error: 0.2404, Coeff of Var: 0.0019

10V
Error: 0.0671, Coeff of Var: 0.0006

10ohm
Error: 48.5352, Coeff of Var: 0.0

100ohm
Error: 8.2285, Coeff of Var: 0.0

1000ohm
Error: 0.0443, Coeff of Var: 0.0

10000ohm
Error: 1.9391, Coeff of Var: 0.0

40000ohm
Error: 5.2247, Coeff of Var: 0.1246

As can be observed, the error is fairly low for all the tested voltages. For resistance, the error is higher especially at the low and high ends. It basically isn't accurate at all at 10 ohms. I also did a test of capacitance and for 100nF it measured 579nF, so basically order of magnitude. For 10uF it measured 11.78uF, so close. I may be able to make capacitance better  (for 100nF) by increasing the sample rate.