Downhole quartz technology...
Our quartz pressure gauge offers superior sensing technology. We wish to highlight:
1) “Quartz Characteristics" - Why is quartz the material choice for pressure measurement?
2) “Quartz Reliability” - Evidence of long term reliability.
3) “Long Term Stability” - The only choice for long tests.
4) “Transient Response” - A simple solution.
Quartz Characteristics
Perfect crystalline structures are perfectly elastic and a perfectly elastic structure has no creep and therefore exhibits no hysteresis. When a force is applied to a piece of quartz the shape of the quartz will change, but when that force is removed, the shape of the quartz will return to its exact original shape. In non-crystalline structures, once the force is removed the material will maintain some residual stresses and never come back to its exact original shape.
However, even though a perfect single crystal of quartz will not drift or creep over time, a quartz sensor assembly will. The metal bellows protecting the crystal, the sputtered metallic surfaces allowing one to connect wires to the crystal, the glues used to bond and assemble the quartz pieces together and even the housing of the sensor are non-crystalline. All of these parts along with the circuit used to measure the output of the crystal are the major sources of inaccuracy for a quartz sensor.
Quartz Reliability
A major reason for choosing a DataCan quartz gauge is its reliability.
- Hybrid Oscillating Circuit.
- Modular Memory Cartridge.
- Super Seal Technology.
The quartz crystal is capable of withstanding temperatures in excess of 225ºC. The corresponding hybrid oscillating circuit is capable of withstanding temperatures in excess of 200ºC.
The DataCan quartz tools, are small and rugged. The modular memory cartridge allows operators to replace the complete surface mount board after exposures to extreme high temperatures.
The short board length reduces the risks of shock and vibration failures by minimizing the mass of the assembly. The locking battery pack further protects the tool from power interruptions.
DataCan’s super seal technology allows the tool to withstand 30,000psi. It also reduces the o-ring extrusion clearance and offers a beveled metal to metal seal surface. The fully welded quartz transducer further eliminates unwanted leaks from causing tool failures.
Long Term Stability
The Quartzdyne pressure transducer offers an exceptional stability over time; a 16,000psi sensor is expected to drift less than 3psi per year. As a side note, all of DataCan's downhole quartz memory recorders are manufactured using Inconel 718. As such, all of DataCan's quartz pressure gauges are resistant to sour service corrosion and can be used in H2S and CO2 environments (as per NACE MR0175).
Transient Response
The DataCan housing design further improves the transient response of the quartz sensor by allowing fluid to directly contact the surface of the pressure transducer. Competitors will often house the pressure transducer inside of an insulating tube, further deteriorating the transient response.