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TDH-21 Seismic Hydrophone
1. Product Overview（TDH-21 Seismic Hydrophone）
TDH-21 seismic hydrophone is specifically designed for the seismic exploration industry and is widely used in Ocean Bottom Cable (OBC) and Ocean Bottom Node (OBN) systems. Its excellent low-frequency response and low self-noise characteristics enable stable and reliable signal acquisition even in deep-water, high-pressure environments. The product features a compact package design (63.5 mm in length and 19.1 mm in diameter), making it easy to integrate into various marine seismic acquisition arrays, especially in node-based systems where space is limited.
2. Key Technical Advantages（TDH-21 Seismic Hydrophone）
(1) Wideband Frequency Response: 2Hz-52kHz flat response, covering primary seismic exploration frequencies and harmonic components
(2) High Sensitivity: -201 dB re 1V/μPa (without preamplifier), directly compatible with most acquisition circuits
(3) Deep Water Capability: Maximum operating depth up to 3500 m, suitable for deep and ultra-deep water seismic operations
(4) Low Self-Noise: Excellent equivalent input self-noise performance, ensuring detectability of weak seismic signals
(5) Flexible amplification: A customizable preamplifier is available based on requirements, with a maximum gain of 40 dB, enabling compatibility with the dynamic range of different acquisition systems.
3. Technical Specifications（TDH-21 Seismic Hydrophone）
(1) Sensitivity (without preamplifier): -201 dB re 1V/μPa; Optional (with preamplifier): -170 dB re 1V/μPa
(2) Frequency Range: 2 Hz-52 kHz
(3) Preamplifier: Not included as standard, customizable (maximum gain 40 dB)
(4) Equivalent Input Self-noise (Typical): < 45 dB re 1 μPa/√Hz @ 100 Hz
(5) Max. Operating Depth: 3500 m
(6) Dimensions (Diameter × Length): 19.1 mm × 63.5 mm
(7) Operating Temperature: -10°C to +60°C
(8) Storage Temperature: -20°C to +70°C
(9) Housing Material: Acoustically transparent rubber / Titanium alloy (optional)
(10) Connector/Cable: Standard two-core waterproof cable, length customizable
4. Typical Applications（TDH-21 Seismic Hydrophone）
(1) Ocean Bottom Cable (OBC): Used as hydrophone array elements to record the seabed seismic wavefield.
(2) Ocean Bottom Node (OBN): Independent acquisition units suitable for four-component (4C) or single-component hydrophone systems.
(3) Deep-water Vertical Seismic Profiling (VSP): Velocity surveys in coordination with downhole tools.
(4) Shallow-water High-resolution Seismic: Engineering site investigations, pipeline route surveys, etc.
