1. After connecting the power cord of the instrument, turn on the power switch, attach the relevant test fixture, and warm up for 10 minutes.
2. Use the "Brightness" adjustment knob to set the brightness of the trace on the instrument display to an appropriate level, but avoid excessive brightness to prevent damage to the oscilloscope tube; use the "Focus" and "Auxiliary Focus" knobs to adjust the trace to be as thin and clear as possible to improve reading accuracy; use the horizontal and vertical position knobs to move the trace to the center of the bottom horizontal line on the screen, and align it with the bottom line for convenient reading during testing.
3. According to the test conditions required for the transistor under test, set the relevant test conditions using the knobs and buttons on the instrument panel.
4. Insert the transistor under test into the port on the test fixture with the correct polarity; the instrument will display a waveform similar to the figure below:
5. Read the amplification factor test value.
Since the amplification factor of a transistor is β = IC/IB, it is necessary to read both the IC and IB values to calculate the amplification factor. The "Current/Div" knob on the instrument panel sets the value of IC per division, and the "Current-Voltage/Step" knob sets the value of IB per step. The IC value is read by the number of vertical divisions occupied by the waveform, while the IB value is read by the number of steps of the waveform. Assuming the test waveform in the figure above as an example: the "Current/Div" knob is set to 10mA, and the "Current-Voltage/Step" knob is set to 1mA. From the waveform in the figure, it can be seen that the waveform occupies 3.4 vertical divisions and has 2 steps. Therefore, the amplification factor is calculated as follows:
β = IC/IB = (10mA × 3.4 divisions) ÷ (1mA × 2 steps) = 34mA ÷ 2mA = 17
6. If further testing is required, repeat steps 4-5. After testing is complete, turn off the instrument power. [4]
