HL48 is an enhanced 24-bit multi-channel near surface seismic instrument in combination of multifunction, high-precision, high speed, high reliability and expandability, is widely used in refraction, reflection, seismic exploration, surface wave survey as well as small marine seismic survey.
HL48 carried out the actual circuit test filtration on a variety of 24-bit A/D and finally selected the multi-channel successive approximation register (SAR) and (¨S-¡Æ) analog/digital converter (ADC), with internal integration of multiple independent high chopper stabilized modulators and FIR digital filters, is dedicated to the demanding multi-channel signal acquisition system. It has excellent AC, DC performance. Compared with similar products, the bandwidth is increased by more than 30%, dynamic range and sensitivity is increased by 44%, achieving the minimum distortion and laying a foundation for high quality acquisition of HL48.
Adopt the high-performance 24-bit A/D converter, with the maximum sampling interval of 20us - the international advanced level.
Acquisition channels 1-48 for selection and settings.
Each channel is configured independently with multi-position preamplifier, and the gain of each channel is set separately, to better ensure distal and proximal signal acquisition.
Embedded microcomputer system based on WinXP, human interface designer, easy to complete data acquisition, processing and storage.
Ultra bright color LED display can still clearly show the waveform in bright light.
Standard waterproof keyboard is easy to use and operate.
Equipped with a high-resolution thermal printer, it can directly print acquired waveforms and annual/monthly inspection reports.
On-site on-off test of wave detector and master cable, online monitoring of waveform noise.
Built-in all-electronic override switch realizes rolling acquisition which can acquire up to 96 channels, and improves field construction and exploration efficiency.
Working bandwidth of 5KHz, applicable to not only UHF engineering surveys, but also low frequency natural seismic monitoring.
Built-in high-quality signal source, the function of setting daily/monthly/annual inspection, to facilitate industry norms self-inspection and application.
2 Technical Parameters
Passband: 0.1Hz~5KHz.
Dynamic range: 144dB (2ms sampling), 110dB(transient state).
Harmonic distortion: Better than 0.003% .
Crosstalk between channels: Better than-90dB.
Common mode rejection: Better than 100dB (<= 100Hz, 36dB).
Background noise: <0.2uV (2ms sampling, 36dB).
Amplitude consistency: Better than 0.3% (2ms sampling, 36dB).
Power supply: supplied by 12V 20% storage battery.
Power consumption of complete machine: less than 30W.
Ambient temperature: -20---+55¡æ.
Storage temperature: -20---+60¡æ; Humidity: 90% RH.
Volume: 342mm x 288mm x 210mm.
Weight: 11.5 Kg for 48-channel; 14 Kg for 96-channel.
Computer: Wide-temperature low-power-consumption military-grade PC104 + embedded IPC. Primary frequency is not less than 1GHZ, memory is not less than 512M, and hard disk is not less than 160G.
Display: 12.1 1024 x 768 dot matrix, low power consumption, ultra bright, and high contrast TFT (True color) LED display.
Peripheral interface: three USB interfaces, COM, CRT display interface.
Acquisition channels: standard 48 channels (8-96 channels optional).
Sampling interval: 20us, 31.25us, 62.5us, 125us, 250us, 500us, 1ms, 2ms, 4ms, 8ms, and 16ms.
Sample length (number of samples): 512, 1024, 2048, 4096, 8192, and 16384 (optional).
Preamplifier Gain: 36, 30, 24, 18, 12, 6, and 0 dB.
Delay time: 0-5000 milliseconds.
Wave filter: Digital low cut, high cut, band pass, notch filter, filtering frequencies are user-selectable.
Data format: Standard SEG-2 format.
Software: xp graphical interface, integrated acquisition and control processing software.
3 Product Features
Digital Filtering Function
Digital filter has a higher precision than analog filter, is an important branch of digital signal processing, with high precision of digital filtering. Compared with analog filter, it has the characteristics of higher signal-to-noise ratio and stability, as well as easy for program control and change of filtering.
HL48 configures powerful digital filter that can realize various types of filtering. Modeling by dedicated filter design software is conducted for the digital filter. To improve computing speed, a variety of programming techniques are used, making filtering calculation and spectral conversion be completed instantaneously. The filter has the functions such as low-cut filtering, high-cut filtering, band pass filtering, band reject (notch) filtering. Filtering band can be set as required by users. Original waveform / original spectrum, waveform after filtering / spectrum after filtering are showed on the same display so that users are allowed to intuitively grasp the filtering effect, which greatly improves the pertinence of filtering function.
Upgrade interface is reserved for the filtering software. Hwaland Company will continue to provide digital filters with superior performances for users.
Preamplifier Gain
Preamplifier gain of each channel can be set separately, to guarantee suitable signal amplitude of distal and proximal end of the master cable.
Navigation Menu Mode
Hwaland Company improves operation friendliness of the application software from details. Based on traditional pull-down menu, navigation menu bar is added, which is more suitable for field operation requirements.
Navigation menu bar is located on the right side of the screen with thick font, is suitable for field viewing operations, avoids the complexity of traditional computer keyboard, and is convenient to guide users to perform software operation.
Built-in Printer
HL48 is equipped with mini thermal printer. It can print acquired waveforms, primary wave time and annual/monthly inspection reports.
Waveforms are selected to print in proportions, i.e. printing 25%-100% of sampling length. Printing contents include date and construction parameters, etc.
One-click Acquisition Operation
In order to facilitate users¡¯ field construction operations, from a practical perspective, parameter setting, data acquisition, archiving & printing as well as other commonly used functions are integrated to realize one-click acquisition and greatly improve the applicability. In addition, operations such as waveform browse, primary wave interpretation, noise monitoring, and wave detector on-off test can be carried out quickly through a combination of keyboard functions.
Built-in All-electronic Override Switch
To improve the efficiency of construction, override switch is built inside. Through rolling direction and rolling channel number settings, the system automatically controls the override switch and transfers the override channel number before each shooting to realize rolling acquisition.
Wave Detector On-off Test
The online test function of wave detector can visually detect the connection status between master cable and detector, reduce errors, and improve construction efficiency.
