Highly stable vibrating wire sensor for monitoring internal temperature in concrete, soil, and rock masses.
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Highly stable vibrating wire sensor for monitoring internal temperature in concrete, soil, and rock masses.
The Geolook G89-V400 Vibrating Wire Temperature Meter is designed for precise, long-term temperature monitoring in geotechnical and structural applications. While many sensors contain internal thermistors for compensation, the G89-V400 is a dedicated primary sensor engineered for extreme durability and frequency-based accuracy. The sensor utilizes the relationship between temperature and the resonant frequency of a tensioned wire. Housed in a hermetically sealed stainless steel body, it is ideal for measuring the thermal gradients in mass concrete during hydration, geothermal monitoring, and tracking seasonal temperature shifts in dams and bridges.
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In large-scale geotechnical projects, distance and time are the enemies of data. Traditional analog temperature probes (like RTDs or Thermistors) rely on resistance changes. Over a 1-kilometer cable, the resistance of the wire itself can change with the weather, causing 'phantom' temperature shifts.
The G89-V400 outputs a frequency. Because the frequency of the vibrating wire does not change regardless of the cable length or moisture in the connections, it provides a 'true' reading every time, even decades after installation.
When pouring massive amounts of concrete for a dam or a bridge pier, the chemical reaction (hydration) generates significant heat. If the center of the concrete gets too hot while the outside stays cool, the resulting thermal stress can crack the structure from the inside out.
The G89-V400 is embedded in arrays to map the 'Heat of Hydration.' This allows engineers to control the cooling process—often by pumping water through internal pipes—to ensure the temperature gradient remains within safe limits during the curing phase.
The sensor works on the principle of differential thermal expansion. A high-strength steel wire is tensioned between two points inside a stainless steel tube. As the temperature changes, the tube and the wire expand or contract at different rates.
This change in physical tension alters the resonant frequency of the wire. An electromagnetic coil plucks the wire and listens to its 'pitch.' This pitch is then converted into a high-precision temperature reading using a factory-supplied calibration polynomial.
Constructed from 316L stainless steel and hermetically sealed, the G89-V400 is designed to be buried and forgotten. It can withstand the high alkaline environment of wet concrete and the high pressures of deep burial in earth-fill dams.
The cable entry is reinforced with a water-blocking seal, ensuring that even if the outer cable jacket is damaged during construction, water cannot travel down the wires into the sensor body.
In large-scale geotechnical projects, distance and time are the enemies of data. Traditional analog temperature probes (like RTDs or Thermistors) rely on resistance changes. Over a 1-kilometer cable, the resistance of the wire itself can change with the weather, causing 'phantom' temperature shifts.
The G89-V400 outputs a frequency. Because the frequency of the vibrating wire does not change regardless of the cable length or moisture in the connections, it provides a 'true' reading every time, even decades after installation.
The sensor works on the principle of differential thermal expansion. A high-strength steel wire is tensioned between two points inside a stainless steel tube. As the temperature changes, the tube and the wire expand or contract at different rates.
This change in physical tension alters the resonant frequency of the wire. An electromagnetic coil plucks the wire and listens to its 'pitch.' This pitch is then converted into a high-precision temperature reading using a factory-supplied calibration polynomial.
When pouring massive amounts of concrete for a dam or a bridge pier, the chemical reaction (hydration) generates significant heat. If the center of the concrete gets too hot while the outside stays cool, the resulting thermal stress can crack the structure from the inside out.
The G89-V400 is embedded in arrays to map the 'Heat of Hydration.' This allows engineers to control the cooling process—often by pumping water through internal pipes—to ensure the temperature gradient remains within safe limits during the curing phase.
Constructed from 316L stainless steel and hermetically sealed, the G89-V400 is designed to be buried and forgotten. It can withstand the high alkaline environment of wet concrete and the high pressures of deep burial in earth-fill dams.
The cable entry is reinforced with a water-blocking seal, ensuring that even if the outer cable jacket is damaged during construction, water cannot travel down the wires into the sensor body.
We are currently updating the specific model configurations and technical datasheets for this product category.