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計測機器 DigiVac Bullseye PiezoのPDF ユーザーマニュアルをオンラインで閲覧またはダウンロードできます。DigiVac Bullseye Piezo 18 ページ。

The most important thing about accuracy is knowing what you need for your process. You should

choose the sensor that meets your needs. All sensors have tradeoffs of cost, type of reading

technology, and accuracy.

For example, a more accurate alternative to the Bullseye Piezo is a 1000 Torr capacitance manometer.

Some can be had at 0.15% of reading and are also isolated. However, they tend to be expensive, don't

travel well (easily damaged), and require frequent maintenance to maintain that accuracy, especially

around 10 Torr. The Bullseye Precision Gauge Piezo was built from the ground up to be rugged and

thrive with field use.

ISOLATED SENSORS

For use in dirty environments or where corrosive gases are in use

The isolated part of the sensor is important. Isolated means that the sensing electronics are

separated and protected from the process gas pressure being measured.

When do you need an isolated sensor?

When measuring clean dry gasses, isolated doesn't matter. Non-isolated sensors where the silicon die

of the piezo resistive encounters clean dry gasses (like air and nitrogen) will work. These electronics

can survive a lifetime exposed to clean dry air and even low humidity or an occasional splash of water

(when not energized).

Isolated is needed in corrosive environments

the silicon die and wires that make up a sensor just like the ocean would corrode a steel bolt thrown

into it. Over time the sensor will degrade and cease to operate. The isolation in the 775i and the

Vac2PSI sensor is achieved through a stainless-steel diaphragm that comes in contact with the media

to be measured, commonly called the wetted surface. These sensors will operate fine in diesel fuel,

gas, nitrogen, alcohol, or other corrosive environments.

The only time these sensors may degrade is when substances calcify on the stainless-steel diaphragm

preventing its movement. If the readings seem sluggish, check the sensor. When in doubt, use an

otoscope to look in the sensor to see if any foreign matter is stuck near the diaphragm. Wash out with

solvent, but do not poke the diaphragm. If the foreign matter is still obvious then it may be time to

replace the sensor. The sensors are easily replaced and have excellent interchangeability. Isolated

sensors are immune to damage from corrosive processes and materials.

: Corrosive gasses on the other hand will corrode

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