Control and monitoring of glove box atmospheres

Continuous trace moisture and oxygen measurement

Introduction:
Glove boxes vary in size and shape but they are all characterized by openings that allow a person to insert their hands into the box. Gloves with long cuffs are tightly sealed around each of the openings on the front panel. When a person inserts their hands and arms into the box the gloves allow the product to be handled while the integrity of the internal conditions remains intact.

Application:
These conditions or micro-environments allow the operator to run processes that are either part of a manufacturing process (e.g. semiconductor industry) or a research project that requires special conditions, for example in the development of new drugs. In many cases, the glove box also has a protective function for the operator, protecting him from exposure to hazardous substances.

Producing a modified atmosphere simply means maintaining a controlled environment with conditions that differ from normal, or ambient conditions. To provide that controlled and pure environment, inert gases are used to blanket the glove box and provide a neutral background environment.

The space inside the glove box is continuously purged with dry, inert gas such as nitrogen, argon or helium. This micro-environment requires monitoring and control.

The technology and instrumentation play an important role in the accurate and continuous measurement of moisture and oxygen levels.

Technologies for monitoring glove box atmospheres:
Panametrics, a Baker Hughes business, develops innovative measurement solutions for gas and liquid applications in many industries including oil and gas, petrochemical, metal heat treating, power, and renewable energy. With over 10,000 glove box atmosphere-monitoring devices installed, Panametrics products prove their performance and reliability every day.

Galvanic fuel cell for oxygen, converting oxygen to electrical energy:
One of the best methods for measuring low-ppm oxygen is galvanic fuel cell technology. This electrochemical cell converts oxygen to an electrical signal. It is self-contained and has a long life. The sensor is insensitive to background gas changes. Galvanic fuel cells are fast, accurate, and easy to use.

Aluminum Oxide for Moisture:
Changing electrical properties with water.
Aluminum oxide is the most widely used technology for trace moisture measurement.
An aluminum oxide sensor consists of a metal base, aluminum oxide layer, and a vapor deposited metal layer on top.
Water molecules entering the aluminum oxide pores will change the electrical properties of the sensor. This electrical response is calibrated to varying moisture levels.
These sensors are cost effective, cover a wide concentration range, and are very fast.

Panametrics Solutions
VeriDri, Moisture Transmitter for Trace Moisture Measurement
Panametrics aluminum oxide moisture sensors have set the standard in process moisture measurement for more than 60 years.
Key benefits
• Large dynamic measurement range
• Many range options are available in dew point and PPMv
• Compact transmitter

oxy.IQ, Analyzer for Trace Oxygen Measurement
Proven galvanic fuel technology provides superior performance.
Key benefits
• Compact, innovative design for easy installation
• Intuitive user interface to easily select range, view diagnostics, trim outputs and perform calibration
• User-selectable ranges, calibration, sensor diagnostics with keypad simplifies programming
• Background gas insensitivity and acid gas sensor options ensure accurate measurement and analysis