The reason why Hawtry X2 Safety Capacitors use μF values or three-digit capacitance codes on the component body, while CQC/VDE/UL safety certificates and test reports use pF as the capacitance unit, is because different application scenarios follow different industry standards.

The capacitance value is exactly the same; only the unit expression method differs.

1. Component Body Marking: Industry Standard for Production, Purchasing, and Engineering Use

1.1 Direct μF Marking Is Common for Leaded X2 Film Capacitors

The capacitance range of X2 film capacitors is typically concentrated between:

0.01μF ~ 2.2μF

In power supply design, purchasing, and production environments, engineers commonly use μF as the communication unit because it is intuitive and requires no conversion.

Examples:

• 0.1μF

• 0.47μF

• 1μF

Using μF directly allows engineers to quickly identify specifications during:

• BOM preparation

• Component selection

• Prototype development

• Production assembly

and reduces the risk of conversion errors.

Some manufacturers also use three-digit capacitance codes. The basic unit of this coding system is pF.

Example:

104

= 10 × 10⁴ pF
= 100,000pF
= 0.1μF

Both marking methods are widely used in the capacitor industry.

1.2 Digit Codes Save Marking Space

The three-digit capacitance code is more compact and suitable for smaller components.

Examples:

• 104

• 224

• 474

For some compact X2 capacitors, the digit code requires less printing space than direct μF marking, making it easier for automated production and laser printing.

2. CQC/VDE/UL Safety Certificates and Test Reports: pF as the Unified Certification Unit

2.1 pF Is the International Measurement Reference Unit

Safety capacitor standards, including:

• IEC 60384-14

• Relevant national testing standards

require capacitance measurement results, type test reports, and certification documents to follow standardized engineering units.

Global certification organizations such as:

• CQC

• VDE

• UL

• ENEC

typically use pF in official certification documents.

The purpose is to ensure:

• Consistent measurement references among laboratories worldwide

• Unified factory inspection standards

• Avoidance of disputes caused by unit conversion differences

2.2 pF Provides More Accurate Capacitance Tolerance Evaluation

X2 safety capacitors commonly have tolerances such as:

• ±10%

• ±20%

Using pF allows more precise evaluation of capacitance limits.

Example:

0.1μF = 100,000pF

For ±10% tolerance:

Acceptable range:

90,000pF ~ 110,000pF

If only 0.1μF is shown on a certificate, the detailed measurement range is less intuitive during:

• Certification review

• Factory audits

• Incoming inspection

2.3 Testing Equipment Uses pF as the Internal Calculation Unit

Professional measurement equipment, including:

• LCR digital bridges

• Safety capacitor test systems

• Laboratory measurement instruments

typically use pF as the basic internal calculation unit.

The test report output is generated directly from the measured value, without additional conversion.

3. Example Comparison: The Values Are Exactly the Same

Example:

Product marking:

0.47μF

or

474

Safety certificate:

470,000pF

Conversion:

1μF = 1,000,000pF

Therefore:

0.47μF = 470,000pF

The electrical specification is completely identical.
Only the unit expression method differs according to the application scenario.

4. Practical Guidelines for Customer Communication and Audits

1. Quotations, BOMs, and Sample Datasheets

Recommended unit:

μF

Reason:

• Easier for engineers to understand

• Consistent with power supply design habits

• Convenient for component selection

Example:

X2 Capacitor: 0.22μF ±10% 275VAC

2. CQC / UL / VDE Certification Documents

Recommended unit:

pF

Reason:

• Required by certification documentation practices

• Based on international measurement standards

• Not a parameter difference

Example:

Certified Capacitance: 220,000pF

3. When Customers Question Different Values

Simply provide the conversion formula:

1μF = 1,000,000pF

Example:

0.22μF = 220,000pF

The product specification is identical.

Conclusion

For Hawtry X2 Safety Capacitors:

• Product marking: μF or digit code → convenient for engineers, purchasing, and production

• Datasheets: μF with pF conversion → clear technical communication

• Safety certificates: pF → unified international certification format

This difference is a normal industry practice and does not represent any inconsistency in product specifications.