When you need a higher level of accuracy in your experiment, you can calibrate the PBB-272B for the best results.
Caution: handle the unit with care as electrocution may be possible.
First, removing the side screws.
Second, remove the screws from the bottom of the unit.
Step 3: Carefully remove the back of the unit and set it aside. Note that the transformer is mounted in the back panel.
Step 4: Set the unit standing on its side so that you can see the digital panel and have stable access to the VR1 and VR2.
Step5: Hook up one of the PBB-272B outputs to a digital meter, in this case, the Mastech MS8050.
Step 6: Now you can turn the unit on. Turn the VR1 clockwise or counterclockwise accordingly so the value in the PBB-272B digital panel for 0~15V matches the value on the digital meter.
Step7: Make sure you move the test lead to the correct port. Then, turn the VR2 clockwise or counterclockwise accordingly so the value in the PBB-272B digital panel for 0~-15V matches the value on the digital meter.
Step8: Turn the unit off, unplug all of the test leads before reassembling the unit. Do a quick test after the reassemble to ensure the adjustment didn’t change during the assembly process.
Calibrate your PBB-272B is a good practice for any electrical engineer since maintenance testing equipment is a big part an engineer work. Furthermore, you can use these step to calibrate simple power supply unit or other similar electronic equipment.
If you want to learn more about these calibration process, you can read How to Test and Calibrate Power Supply Voltage/Current Readings.