Bruel & Kjaer 2425 Electronic Voltmeter

The Brüel & Kjær 2425 is a precision electronic voltmeter designed for a wide array of voltage measurement applications. It offers versatile measurement modes, including true RMS, Average, +Peak, -Peak, and Max. Peak, across a broad frequency range of 0.5 Hz to 500 kHz. This instrument is capable of measuring voltage levels from 100 μV up to 300 V, with selectable meter damping characteristics (Fast and Slow) and a Peak Hold function for capturing transient signals. The 2425 also provides AC and DC outputs for recording purposes and can be powered by either mains or battery. Its Average Fast mode adheres to the ANSI Standard C16.5-1961, enabling its use as a volume indicator for audio and telephone line analysis.

### Technical Specifications

* **Measurement Modes:** True RMS, Average, +Peak, -Peak, Max. Peak
* **Voltage Measurement Range:** 100 μV to 300 V full-scale deflection (FSD)
* **Frequency Response:** 0.5 Hz to 500 kHz (0.5 MHz)
* **Accuracy (RMS Measurement):** ±0.5 dB for signals with crest factor up to 5:1 (14 dB)
* **Dynamic Range (RMS Rectifier):** > 40 dB
* **Crest Factor Capability:** 5:1 (14 dB)
* **Meter Damping (Time Constants):** Selectable “Fast” and “Slow”
* **”Fast” Response:** ±0.2 dB from 20 Hz to 0.2 MHz; ±0.5 dB from 0.2 MHz to 0.5 MHz
* **”Slow” Response:** ±0.2 dB from 2 Hz to 0.2 MHz; ±0.5 dB from 0.5 Hz to 0.5 MHz
* **Average Measurement:**
* “Fast” response for standard VU measurements.
* “Slow” response.
* **Peak Measurement:**
* Selectable for +Peak, -Peak, and Max. Peak detection.
* Input time constant: 50 µs (“Fast”), 500 µs (“Slow”).
* “Hold” leakage rate: < 0.05 dB/s ("Fast"), < 0.005 dB/s ("Slow"). * "Reset" discharge time: 2.7 s ("Fast"), 30 s ("Slow") from full-scale deflection. * **Peak Hold Functionality:** Captures very short transient signals. * **Signal-to-Noise Ratio (300 kHz bandwidth):** * 1 mV Range: > 40 dB
* 3 mV Range: > 50 dB
* **Meter Scale:** Standard linear scale; interchangeable scales for dBm and VU measurements available.
* **ANSI Standard Compliance:** Average Fast mode conforms to ANSI Standard C16.5-1961 for “vu” measurements.

### Electrical Characteristics

* **Input:** Standard BNC socket
* **Input Impedance:** 1 MΩ || 47 pF
* **Max. Input Voltage:** 250 V DC; 110 V peak in “mV” ranges, 600 V peak in “V” ranges.
* **Amplifier/Attenuator Range:** -50 dB (300 V FSD) to +60 dB (1 mV FSD) in 10 dB steps.
* **AC Output:** Line-level signal via rear panel socket, suitable for recording.
* Output Voltage: 1 V RMS at full-scale deflection.
* **DC Output:** Via 7-pin DIN socket on rear panel.
* Output Voltage: 1 V DC ± 2% at full-scale deflection.
* Max. Output: 5.6 V.
* Output Resistance: < 1 Ω. * Minimum Load: 1 kΩ. * **External Time Constant Input:** For connection to other recording or signal processing equipment. A capacitor of 2.5 µF connected to this input increases the RMS averaging time and Peak decay time by 10 s. A resistor can also be used to modify the Peak decay time.### Physical Characteristics* **Power Source:** Mains or external battery operation. * **Dimensions:** Specific dimensions not detailed in the provided sources. * **Weight:** Specific weight not detailed in the provided sources.### Compatibility* **Designed for use with:** Brüel & Kjær vibration meters (as per short description, though the technical details focus on its function as a standalone voltmeter). * **Recording Equipment:** Compatible with chart recorders and other data recording equipment via AC and DC outputs. * **External Meter Time Constants:** Connection port available for external time constants. * **Remote Meter Reset:** Capable of remote meter reset via a rear panel DIN socket.### Applications* General purpose voltage measurements. * Measurement of true RMS, Average, +Peak, -Peak, and Max. Peak values. * VU measurements for audio and telephone line analysis. * Recording of AC and DC signals. * Measurement of impulses and other transient signals. * Use as a compressor amplifier.Why Choose Aumictech for Brüel & Kjær 2425? At Aumictech, we specialize in supplying high-end electronic test and measurement equipment. Whether you need precise voltage measurements, reliable transient signal capture, or adherence to industry standards like the ANSI C16.5-1961 for VU metering, our team ensures the Brüel & Kjær 2425 delivers maximum performance for your application.