Hydro-Trans – Hydrogen Transmitters

Thermal Conductivity Transmitter

Process Online Gas Analyzer

The Hydro Transmitter from Roscid Technologies sets the standard for thermal conductivity detector-based applications within the process control industry. As a rugged transmitter, packaged in a weatherproof housing, the Hydro Trans is suitable for use in harsh, hazardous outdoor environments. Using a novel, solid-state thermal conductivity sensor, this cost-effective transmitter can be configured to detect H₂, He, N₂, Ar, CO₂ or several other gases of interest in binary or multi-component sample gas mixtures.

• Features of the analyzer

• Unique, long-life, solid-state, TC sensor design
• No reference gas requirements
• Temperature controlled TCD providing excellent zero and span stability over a wide temperature range
• Intrinsically safe design allowing for use in hazardous areas
• Robust, weatherproof housing suitable for outdoor installations
• Linearized 4-20 mA signal output
• Small, space-saving, compact design
• Simple to install

• Applications

• Power plant: H₂ purity analysis on turbine generator purge gas
• Petrochemical plant: H₂ purity analysis on H₂ / HC recycle gas streams, redesulfurization, and tail gas treatment processes
• Air separation plant: Bulk gas purity monitoring and welding / diving / cal gas cylinder verification
• Heat treating: Annealing furnace blanket gas monitoring
• Electrolysis: H₂ purity analysis in O₂
• Fuel cell development: Methane feed gas purity analysis and reformer efficiency

Sensor operating principle

The thermal conductivity sensor measures the concentration of a specific gas between a hot surface resistor and an ambient temperature reference resistor using the thermal conductivity coefficient of the gas itself.

Sensor description

The sensor structure consists of an integrated heater located on a thin electrical and thermal insulating membrane. Two thin film resistors are used for heating and measuring the temperature of the membrane. Two resistors are integrated on the silicon beside the membrane for the compensation of the ambient temperature changes. Gases which have a lower density than air (CH₄) cause a decrease on the surface membrane temperature. On the other hand, gases with densities heavier than air (CO₂) increase the temperature of the measuring resistor.

Features

• Stable long-term operation
• Physical method for gas concentration measurement
• Low power consumption