• For capacitive touch sensors, including Capacitive Touch Screen monitors, first check their appearance. Check that the surface of the screen is flat and smooth, and that there are no scratches, cracks, or visible stains. Because these defects may interfere with touch operation, for example, scratches may cause inaccurate positioning of touch points, affecting the accurate judgment of the touch position of the capacitive touch display.

2.Connectivity detection

• Line connection check：If it is a stand-alone capacitive touch sensor module or a capacitive touch screen overlay connected to the device, check whether the connection line is intact. For wires connected, check the wires for signs of breakage, breakage, or poor contact. You can use the resistance file of the multimeter to check the continuity of the line to ensure that the signal can be transmitted properly.
• Interface checks：Check whether the connector of the sensor or capacitive touch screen matches the connector of the motherboard and is securely connected. Loose interfaces may result in loss or instability of the touch signal, so make sure that the pins of the interface are not deformed, bent, or corroded.

3.Basic functional testing

• Single-touch testing：For capacitive touchscreens, use your finger to tap various locations on the screen, including center, edge, and corner areas. Observe whether the device accurately recognizes the position of the touch point and triggers the corresponding action, such as whether the touch point coordinates are displayed correctly in the test software. For ordinary capacitive touch sensors, check whether the expected change in electrical signal can be produced when touched. Normally, a touch of a finger causes a change in the capacitance of a capacitive touchscreen, and the device detects and reacts to this change.
• Multi-touch test (for capacitive touch screens)：Touch the screen with multiple fingers at the same time, such as two fingers to zoom and three fingers to switch apps. Check whether the capacitive touch screen can correctly recognize multiple touch points, and perform corresponding functions according to the preset multi-touch logic, such as correctly zooming the screen, switching windows, etc. This requires a capacitive touch screen with good multi-touch recognition technology to achieve an accurate functional response by detecting a combination of capacitance changes caused by multiple touch points.

4.Sensitivity test

• Touch force sensitivity：Touch the capacitive touch screen or capacitive touch sensor with different forces. From very light touches to slightly hard touches, see if the device is effective at detecting touch at different pressures. For example, in some applications that require high-precision touch, such as drawing software, even very light touches should be able to be accurately recognized, while for some applications with frequent operations, it may be necessary to be able to withstand a certain amount of force without misjudgment or damage.
• Touch area sensitivity：Touch a capacitive touchscreen using touch objects of different sizes, such as stylus of different thicknesses or different parts of your fingers. Observe how well the screen responds to different touch areas, as the size of the touch area affects the amount of capacitance change. A good capacitive touchscreen should be able to accurately judge touch events based on changes in touch area, rather than error responses because the touch area is slightly larger or smaller.

5.Anti-interference ability test

• Electromagnetic interference testing：Place devices with capacitive touch screens or capacitive touch sensors in an environment where there is electromagnetic interference, such as near large motors, microwave ovens, etc., that are in operation. Observe whether the capacitive touch screen will be mistouched, touch malfunctioning, or abnormal display. An electromagnetic interference simulator can be used to simulate interference of varying intensities to determine the immunity of a capacitive touch screen or capacitive touch sensor.
• Electrostatic interference test：Static electricity is generated around the capacitive touch screen or capacitive touch sensor through an electrostatic generator. Observe if it is affected by static electricity and exhibit abnormal behavior, such as a faulty touch signal or a device restart. Because in actual use, electrostatic phenomena are more common, and good antistatic properties can ensure the stable operation of the equipment.