4374
2Pages

Catalog excerpts

P R O D U C T D ATA Piezoelectric Charge Accelerometer Types 4374 and 4374-L Uses • • • • • High-level, high-frequency measurements Measurements in confined spaces Measurements on delicate structures Vibration testing and analysis Measurements in high-temperature environments Very low weight Integral cable Flat base Extremely high resonance frequency Small size Description Type 4374 is a subminiature planar shear accelerometer with extremely low weight and high resonance frequency. It features an integral side cable that terminates with a 10–32 UNF connector and is mounted on the test object with an adhesive. The housing material is titanium. Each accelerometer is calibrated using random excitation and 1600-line FFT transformation to provide a high-resolution (amplitude and phase) frequency response. This yields a unique characterization and secures the integrity of your vibration measurements. Minimum required clearance for cable, 7.0 The difference between Type 4374 and Type 4374-L is the piezoelectric element. PZ 27 is the piezoelectric element used in Type 4374 and PZ 23 is used in Type 4374-L. Integral low-noise coaxial cable, 10–32 UNF-2B piezoelectric elements is collected between the housing and the clamping ring. Characteristics This piezoelectric accelerometer may be treated as a charge source. Its sensitivity is expressed in terms of charge per unit acceleration (pC/ms–2, pC/g). The planar shear design consists of two rectangular slices of piezoelectric material and two seismic masses arranged on the broad sides of a rectangular centre post. They are held in position using a high tensile strength clamping ring that isolates the piezoelectric elements from the base. The ring also prestresses the piezoelectric elements to give a high degree of linearity. During vibration, the charge produced by the The sensitivity given on the calibration chart is measured at 159.2 Hz with 95% confidence level using coverage factor k = 2. The upper frequency limits given on the calibration chart are frequencies where the deviation from the reference sensitivity at 159.2 Hz is within ±10%. The upper frequency limit is approximately 30% of the mounted resonance frequency. This assumes that the accelerometer is correctly mounted on the test structure − poor moun ng can have a marked eﬀect on the mounted resonance frequency. The lower frequency limits and phase response are determined by the built-in preamplifiers. The lower frequency limits are given in the specifications for deviations from

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Fig. 2 Typical frequency (left) and high-frequency (right) response curves for Type 4374 Sensitivity [%] Phase [Degrees] Amplitude Phase Phase [Degrees] Amplitude Phase Specifications – Charge Accelerometer Types 4374 and 4374-L Ordering Information All values are typical at 25 °C (77 °F) unless measurement uncertainty is stated Type 4374 Type 4374-L Both types include the following: • Carrying box • Calibration chart • AO-0038-D-012: Low-noise coaxial cable, 10–32 UNF connectors, length 1.2 m • JJ-0032: Adapter, 10–32 UNF (F) connectors Frequency Range (±10% limit) Mounted Resonance...

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4374 2Pages

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4374
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