Avoid False Readings When Vacuum Sensors Fail
Ever feel like this guy?
Damage to sensors and units alike is an inevitable facet of field work that can put undue stress on even a well-prepared crew, especially when time is of the essence.
Vacuum sensors are calibrated in air. However, sensor contamination can occur easily in real-world applications leading to failure or false readings.
Having multiple back-up vacuum sensors on hand that have already been factory calibrated to your specific vacuum gauge can save time, stress, and avoid the risk of inaccurate readings. Read on!
Some sources of sensor contamination:
- Vacuum process byproducts
- Improper shut down of the vacuum pump after evacuation or power loss
- Oil back streaming from vacuum pumps
If the sensor/tube resides in a vacuum coating application it can become contaminated by the gases involved in the system. Many times it is oil vapor, but can be just about anything.
Other sources of vacuum sensor failure include: damage in structure due to fatigue, erosion, impact damage and corrosion.
Review here how swapping any given tube onto the unit is unlikely to produce the most accurate results. Each unit is calibrated to a specific sensor, all of which have small electrical differences between them, and the calibration data will be different for any given unit/sensor pair. Once a specific unit is calibrated to a specific sensor, they can be considered a mated pair.
Will an emergency non-calibrated replacement tube work for you?
It depends on two factors:
1. The pressure range that is relevant to your work
2. The need/lack of need for pinpoint accuracy in your pressurized system
Our Bullseye Precision Gauge (BPG) can be supplied with any number of replacement sensors that are individually factory calibrated to work perfectly with the gauge and require minimal user effort in order to be vacuum-ready. This option is outlined in the following application note.