Precautions for the use of oscilloscopes
For the safety of the instrument operator and instrument safety, the instrument works properly within the safety range to ensure that the measurement waveform is accurate and the data is reliable, it should be noted:
1. users such as the need to measure switching power supply (switching power supply primary, control circuits), UPS (uninterruptible power supply), electronic rectifiers, energy-saving lamps, inverters and other types of products or other electronic equipment and utility AC220V can not be isolated from the floating ground signal test, must use the DP100 high-voltage isolation differential probe.
2. General-purpose oscilloscopes by adjusting the brightness and focus knob to minimise the diameter of the point of light in order to make the waveform clear and reduce the test error; do not make the point of light stays at a point of immobility, otherwise the electron beam bombardment of a point in the formation of a dark spot on the fluorescent screen, damage to the fluorescent screen.
3. General oscilloscope shell, signal input BNC socket metal outer ring, probe earth wire, AC220V power socket earth wire end are connected. If the instrument is not used when the earth line, directly with the probe on the floating ground signal measurement, the instrument will produce a potential difference relative to the earth; the voltage value is equal to the probe grounding line in contact with the equipment being measured between the point and the earth's potential difference. This will bring serious safety hazards to the instrument operator, oscilloscope, and the measured electronic equipment.
4. Measurement systems - such as oscilloscopes, signal sources; printers, computers and other equipment. Electronic equipment under test - such as instruments, electronic components, circuit boards, power supply for the equipment under test, etc. The equipment grounding wire must be connected to a common ground (earth).
5. TDS200/TDS1000/TDS2000 series digital oscilloscopes, when used with probes, can only measure the waveforms of signals (the signal under test - signal ground is the earth, and the output amplitude of the signal terminal is less than 300V CAT II). It is absolutely not possible to measure the floating ground signal of the utility AC220V or electronic equipment that cannot be isolated from the utility AC220V. (Floating ground can not be connected to the earth, or cause damage to the instrument, such as testing the induction cooker.)
Other precautions in the use of oscilloscope
(1) Thermal electronic instruments in general to avoid frequent switching on and off, oscilloscopes are also so
(2) If the waveform is found to be subject to external interference, ground the oscilloscope case.
(3) Turn the glow adjustment knob to the bottom along the counterclockwise direction before switching off the oscilloscope, so that the brightness is reduced to a minimum, and then disconnect the power switch.
(4) When observing the bright spot on the screen and adjusting, the brightness of the bright spot should be moderate, not too bright
(5) "Y input" voltage should not be too high, so as not to damage the instrument, in the maximum attenuation should not exceed 400 V. "Y input" wire hanging in the air, by the external electromagnetic interference interference waveforms, should be avoided!
