1. What is a sensor?

　　A sensor is a device used to measure various physical quantities, such as temperature, pressure, speed, tilt angle, etc.

　　2. What is a tilt angle?

　　A tilt angle is the angle of inclination, a special type of angle, generally referring to the angle between a measured plane and the horizontal plane.

　　3. What is a tilt angle sensor?

　　A tilt angle sensor is a type of sensor used to measure tilt angles.

　　4. What is a horizontal plane?

　　Roughly speaking, it is the plane formed when water is completely at rest. Why add the word 'relative'? Because there are no absolutely stationary objects; rest is always relative, in relation to another object. There are infinitely many planes parallel to this plane. In fact, the definitions of horizontal plane and plane are concepts in physics and mathematics that help us understand the real world or serve as basic concepts to discover physical and mathematical laws.

　　5. What does the output method of a tilt angle sensor mean?

　　The output method is divided into two aspects: one refers to the physical output method, and the other refers to the electrical output method.

　　6. How many types of physical output methods are there for tilt angle sensors?

Typically, there are cable outputs and connector outputs. For cable outputs, the length and color coding should be considered. For connector outputs, attention should be paid to the number of cores and pin definitions.

　　7. What problems might arise with cable outputs?

　　When purchasing products, if it is a cable output, it is best to check the manual for the manufacturer's standard output length. Then, based on your application and installation requirements, determine your cable length. If increased, it will involve changes in price, so it is advisable to leave some margin to prevent insufficient length later.

Sometimes customers have special requirements, such as cable + connector methods, as well as internal terminal wiring methods, which are less common.

　　8. What problems might arise with connector outputs?

　　When purchasing tilt angle sensor products, if it is a cable output, it is best to check the manual for the manufacturer's standard output length. Then, based on your application and installation requirements, determine your cable length. If increased, it will involve changes in price, so it is advisable to leave some margin to prevent insufficient length later.

　　Sometimes customers have special requirements, such as cable + connector methods, as well as internal terminal wiring methods, which are less common.

　　9. What is the electrical output method of a tilt angle sensor?

The electrical output method refers to the electrical connection method with the upper computer, which can be divided into many types. Broadly, it can be classified into two categories: analog output and digital output.

　　10. What is an analog output tilt angle sensor?

　　Analog output refers to output signals that are analog signals, such as voltage output and current output.

　　11. What is a digital output tilt angle sensor?

　　Digital output is relative to analog output. There are many types of digital interfaces, such as RS232, TTL, RS485, CAN, PWM, and the rare RS422 interface, SII interface, as well as other master-slave communication methods.

　　12. What is the typical range for voltage output?

　　Typically, it is 0~5V DC output, with some being 0.5~4.5V DC output, and others being 0~10V DC output. In most cases, the output method is 0~5V.

　　13. When should a 0~10V output tilt angle sensor be chosen?

　　Based on current understanding, if the upper computer is a Siemens PLC controller, it may be limited by tight interface resources or constraints, leading to the use of 0~10V output, which is encountered in the photovoltaic industry.

　　14. Why develop a 0.5~4.5V DC output?

　　In special cases, users want to determine whether the sensor is functioning normally. If they see a voltage output of 0~0.5V on the display, it serves as a reference for troubleshooting, hence the use of a 0.5~4.5V output tilt angle sensor.

　　15. What are the advantages of a 4~20mA current output tilt angle sensor?

　　4~20mA output was previously quite common and is considered traditional because digital circuits were not widely used back then. However, in the last 20 years, digital circuits have become widespread, so this form is gradually being used less. Nevertheless, considering that some controllers, upper computers, and secondary instruments still have such interfaces, some customers still choose this interface due to historical transition reasons. However, 4~20mA has an advantage: it allows for long-distance transmission, unlike voltage output, which experiences significant signal attenuation after passing through long cables.

　　Although the output voltage of the voltage type remains unchanged, the longer the cable, the smaller the voltage at the load end. The current type output remains the same at both the output and load ends. Therefore, when your upper computer is more than 50 meters away from the sensor, for stable and reliable signals, 4~20mA output is one of the choices.

　　16. For current output tilt angle sensors, what are two-wire and three-wire systems?

　　Please see the diagram below; it is very intuitive and clear. Figure 1 is a two-wire system, and Figure 2 is a three-wire system.

Figure 1. Two-wire current output

Figure 2. Three-wire current output

　　Single-axis two-wire system, dual-axis three-wire system. Note not to overlook the load resistance during use.

　　17. What is the wiring system for voltage output tilt angle sensors?

　　For single-axis voltage output tilt angle sensors: power +, power -, voltage output 1 channel, which is a three-wire system; for dual-axis voltage output tilt angle sensors: power +, power -, voltage output 2 channels, which is a four-wire system.

　　18. What parameters do tilt angle sensors have?

　　Tilt angle sensors have many indicators, such as single-axis or dual-axis, range, accuracy, resolution, output method, protection level, installation method, response frequency, repeatability, long-term stability, zero offset, etc.

　　19. What are the most important and critical parameters for an inclinometer?

　　For an inclinometer, the most critical parameters are accuracy, stability, measurement range, and protection level.

　　20. How to correctly understand the accuracy issue of an inclinometer?

　　When selecting an inclinometer, customers, especially those who have never encountered an inclinometer before, often find themselves confused about accuracy. They do not know what level of accuracy to choose, often setting it too high or too low, resulting in an inappropriate selection, which can lead to issues with the rationality of the choice.

　　Please remember that the accuracy referred to by most people is often the accuracy at room temperature (25°C). Many manufacturers do not specifically remind you of this, but in actual use, the ambient temperature is always changing. Therefore, the accuracy will definitely be worse than this. As for how much worse, it depends on how much the ambient temperature changes, whether the sensor has temperature compensation, and how effective that temperature compensation is. So do not just look at the manufacturer's stated accuracy at room temperature and assume it is sufficient; one must comprehensively consider the intrinsic nature and meaning of the accuracy parameter.