Why does a good variable reluctance resolver require a CPK (Process Capability Index) ≥ 1.33? The main reasons are as follows:

Firstly, it is necessary to understand what CPK is. CPK is a process capability index used to measure whether a production process can consistently produce products that meet specification requirements. The higher the CPK value, the stronger the production process capability and the more stable the product quality. CPK1.33 is generally considered to have good process capability, while 1.0 is the lowest acceptable standard.

What is a variable reluctance resolver? It is a sensor used to measure rotation angle or position, utilizing the magneto resistance effect to detect changes in the position of the rotor. These types of devices are typically used in applications that require high precision and reliability, such as industrial automation, robotics, automotive electronics, etc.

So, why does this type of device require a CPK of 1.33?

1. * * High precision and reliability requirements**

Magnetic reluctance rotary transformers are commonly used in high-precision scenarios such as industrial automation and automotive electronics, and their performance (such as sensitivity and linearity) must strictly comply with specifications. CPK=1.33 indicates that the production process has high stability and consistency, ensuring that each product meets strict tolerance requirements and reducing the impact of performance fluctuations on the system.

2. * * Reduce defect rates and quality costs**

CPK=1.33 corresponds to a level of approximately 4 σ (Six Sigma standard), with a defect rate of approximately 63ppm (per million opportunities). This ability significantly reduces the probability of non-conforming products, avoiding rework, repair, or recall, especially suitable for fields with extremely high safety requirements (such as automobiles, aerospace).

3. Cumulative error control of complex processes**

The manufacturing of reluctance rotary transformers involves processes such as magnetic material processing and precision machining, and small deviations in each step may be superimposed. A high CPK value ensures sufficient process capability at each stage, thereby suppressing overall errors and ensuring consistent performance of the final product.

4. Industry standards and customer requirements**

The automotive and other industries typically require a CPK ≥ 1.33 as a supplier admission requirement. If the product is used in such fields, meeting this standard is a necessary condition for entering the market, while enhancing customers' trust in quality.

5. Robustness of adaptation process offset**

CPK not only measures process dispersion, but also considers center offset. CPK=1.33 indicates that even with some deviation, the product can still stably fall within the specification range, which is crucial for sensors that require long-term stable operation.

That is to say, CPK=1.33 is the gold standard for the manufacturing process capability of reluctance rotary transformers, ensuring high consistency, low defect rate, and meeting the stringent requirements of the industry, ultimately ensuring the reliability and performance of the product in critical applications.