EN 60444-4:1997

Overview

EN 60444-4:1997 (adopted as SIST EN 60444-4:2002) specifies a standard method for measuring quartz crystal unit parameters using the zero phase technique in a pi‑network. The standard covers the measurement of the load resonance frequency (fL) and load resonance resistance (RL) for quartz crystal units up to 30 MHz, and how to calculate other derived values from those measurements. The method is based on observing the change in resonance frequency when a known load capacitance is inserted in series with the crystal unit.

Key topics and requirements

• Zero phase technique: Uses phase behaviour in a pi‑network test circuit to identify resonance points reliably.
• Pi‑network measurement setup: Defines the test configuration conceptually (pi-network with series load capacitance) used to obtain fL and RL.
• Load capacitance insertion: Specifies the principle of measuring the frequency shift caused by inserting a series load capacitor to determine load resonance characteristics.
• Parameters covered: Primary focus on load resonance frequency (fL) and load resonance resistance (RL), plus guidance for calculating other derived values from the basic measurements.
• Frequency range limit: Applies to quartz crystal units up to 30 MHz.
• Standard harmonization: EN 60444-4 corresponds to IEC 60444-4:1988 and is part of the EN/IEC family for piezoelectric crystal measurement methods.

Applications and practical value

• Production testing and quality control for quartz crystal manufacturers to verify fL and RL.
• Component characterization for oscillator and resonator design where accurate load resonance data is required.
• Metrology laboratories performing standardized measurements for specification and certification.
• R&D teams evaluating crystal behavior under different load conditions and deriving equivalent circuit parameters.
• Test engineers integrating crystal parameter data into circuit simulations and reliability assessments.

Who should use this standard

• Crystal and resonator manufacturers
• Electronic component test labs and calibration services
• Design engineers for timing devices and oscillators
• Quality assurance and compliance teams requiring standardized measurement procedures
• Metrology institutes implementing traceable quartz measurements

Related standards

• IEC 60444-4:1988 - original international publication on the same method (EN 60444-4 is aligned with IEC 60444-4).
• Other parts of the IEC/EN 60444 series cover alternative measurement techniques and parameter definitions for piezoelectric quartz units (refer to the IEC/EN index for specifics).

Keywords: quartz crystal unit, load resonance frequency fL, load resonance resistance RL, zero phase technique, pi‑network, EN 60444-4, IEC 60444-4, measurement up to 30 MHz, crystal parameter measurement.