The Model DHA-7 downhole hydrophone array is designed for high-resolution seismic borehole imaging. The DHA-7 is suited for use in cased and uncased, water-filled, narrow-diameter boreholes, and is easily deployed by hand or with a small winch. With up to 24 channels in a single cable, the DHA-7 allows for fast and efficient high resolution downhole and crosshole data collection!
We manufacture the DHA-7 with unique proprietary polymer hydrophones (no ceramics) in-line molded into a fully integrated, triple-sealed multi-conductor cable. Non-shattering polymer material make possible superior performance and durability under the rigors of borehole applications and provide a stable signal response up to 10 kHz. Custom hydrophone group intervals (up to 5 meters) and multi-borehole configurations are available to tailor the system to meet your needs. The DHA-7 is terminated topside with a 61-socket connector to easily connect to our seismographs such as the Geode or ES-3000. All DHA-7 downhole hydrophone arrays are manufactured and assembled in the USA, and come with an industry leading warranty.
Features and benefits
- Adaptable: The DHA-7 is well suited for high-resolution downhole, VSP, and crosshole surveys
- Unmatched Engineering: State-of-the-art polymer hydrophones provide superior, stable response
- Impressive Noise Suppression: Unique design isolates vibration and suppresses cable-related noise
- Easily Portable: Small diameter cable and light weight per foot make for easy deployment in the field.
- Built Rugged: Reliably performs under the rigors of borehole applications; designed with the field in mind.
- Worldwide Distribution: No export license required!
- Sensor type: Proprietary Polymer.
- Sensors per group: One.
- Frequency response: 10 Hz to 10,000 Hz ± 1.0 dB.
- Capacitance: 5 nF at 22˚C.
- Sensitivity: -197 dB re 1 Volt per 1 μPa.
- Sensitivity with depth: < 1.0 dB over 400 m depth.
- Sensitivity with acceleration: < -70 dB re 1 Volt per g.
- Type: Ultra-low noise differential.
- Gain: 6 dB.
- Current: 10 mA per channel.
- Power: ±12V DC Model DHA Battery Pack on surface.
- Type: Multi-conductor with polyurethane jacket.
- Topside: Y-type with one 61-socket connector (or 27-socket connector) and one 4-pin connector.
- Tail: 1m (3.28ft) long with stainless steel swivel and 6 kg (13.2 lb) weight.
- Maximum total length: 400 m (1,300 ft) (lead plus active section).
- Strength member: Zylon center core.
- Outside diameter: 13.5 mm (0.53 in).
- 12 channels: 0.12 kg/m (0.08 lb/ft).
- 24 channels: 0.15 kg/m (0.10 lb/ft).
- Bend radius: 12.7 cm (5 in).
- Working load: 273 kg (600 lb).
- Breaking strength: 1,364 kg (3,000 lb).
- Channels: 12 or 24 standard; other counts available*.
- Group Interval: 1 to 5 m (3 to 15 ft) standard; other intervals available with a minimum of 0.5 m (18 in)*.
- Outside diameter (hydrophone): 41.3 mm (1.63 in).
- Length (hydrophone): 30.5 cm (12 in).
- Weight (hydrophone): 0.16 kg (0.35 lb).
- Bend radius: 22.9 cm (9 in).
- Operating maximum: 400 m (1,300 ft).
- Operating range: -10˚C to +70˚C (+14ºF to +158°F).
- Storage range: -40˚C to +70˚C (-40˚F to + 158˚F).
*Please contact the factory to discuss your requirements.
Shipping Weights & DIMS
|Contents||Dimensions (L x W x H)||Weight|
|Case 1 - 400m DHA-7 Hydrophone w/ battery pack & extras||48in x 40in x 36in
122cm x 102cm x 92cm
|Case 2 - Geode Seismograph||12in x 14in x 8in
26cm x 31cm x 18cm
- Downhole and Crosshole Surveys: Ideal for shallow gas and mining investigations, imaging of faults and fractures, stratigraphy, voids, and underground structures. Accurately determine soil, rock and reservoir properties
- Engineering Applications: Foundation studies, earthquake engineering, and more.
- Research and Teaching: Easily connect to any 61 pin Seismograph like our Geode Exploration Seismograph. No expensive machinery required for deployment.