What the calculator is for 计算器适合解决什么问题
The calculator gives a first-pass pumping speed estimate from chamber volume, initial pressure, target pressure, pump-down time and correction factor. 选型计算器根据真空容积、初始压力、目标压力、抽气时间和修正系数，给出初步抽速估算。
It does not automatically replace engineering review because leakage, vapor, dust, gas load, piping and duty cycle can change the final pump selection. 它不能完全代替工程复核，因为漏气、水汽、粉尘、气体负载、管路和工作周期都会影响最终选型。
Formula used for preliminary sizing 初步估算使用的公式
The current tool follows the internal Excel formula record: S = 2.3038 x K x V / t x log10(P1/P2). V is chamber volume, P1 is initial pressure, P2 is target pressure, t is pump-down time and K is the correction factor entered by the user. 当前工具按内部 Excel 公式记录计算：S = 2.3038 x K x V / t x log10(P1/P2)。V 是真空容积，P1 是初始压力，P2 是目标压力，t 是抽气时间，K 是用户输入的修正系数。
The output is shown in both L/s and m³/h. The conversion is 1 L/s = 3.6 m³/h. 结果会同时显示 L/s 和 m³/h。换算关系为 1 L/s = 3.6 m³/h。
When to ask for engineer review 什么时候需要工程复核
Ask for review when the process has water vapor, dust, chemical gas, frequent cycling, long piping, unknown leakage or strict final pressure requirements. 如果工况包含水汽、粉尘、化学气体、频繁循环、长管路、漏气未知或极限压力要求严格，建议进行工程复核。
For quotation, send the calculator result together with voltage, frequency, application and destination country. 询价时请把计算结果、电压、频率、应用场景和目的国家一起发送。