XMTCpro hydrogen furnace atmosphere hero

3. September 2026 by Bohuslav Bobrik Bohuslav Bobrik

Hydrogen Content Measurement Ensures Optimal Quality in Metal Heat-Treating Furnaces

APPLICATION NOTE

Hydrogen Content Measurement Ensures Optimal Quality in Metal Heat-Treating Furnaces

Summary

Metal parts, alloys and sheet steel are heat-treated in furnaces at elevated temperatures using controlled hydrogen/nitrogen atmospheres to achieve the desired metallurgical properties and to prepare surfaces for coating. Hydrogen concentration in the furnace atmosphere must be precisely controlled to optimize the finished product’s yield and quality.

Application

Fig. 1: Panametrics XMTCpro thermal conductivity analyzer used to monitor hydrogen content in a heat-treating furnace atmosphere.

Hydrogen-nitrogen mixtures are used to reduce metal oxides. At elevated temperature, hydrogen reacts with the oxide layer to produce water vapor, leaving a bright, shiny, defect-free metal surface. Hydrogen is also injected into furnace annealing zones for controlled jet cooling of the material. Accurate, repeatable hydrogen measurement is essential to optimize yield and minimize scrap.

Gas measured	Hydrogen (background gas: nitrogen)
Measurement range	0 – 100% hydrogen
Process temperature	1000 – 2500°F (538 – 1371°C)
Pressure	Atmospheric
Measurement principle	Thermal conductivity

Benefits:

Automated field calibration
Reliable sensor – no chemical reaction or gas adsorption required
Rugged design for demanding environments
Turnkey system with simultaneous hydrogen, trace oxygen and trace moisture analysis

Challenge

A furnace environment is a demanding place to install a sensor: temperatures are high, and the furnace gas carries particulates including vaporized metal, metal oxides, oils and soot. A sample of furnace gas must be extracted and cooled using a vacuum pump or eductor together with a series of filters. The harsh, dirty environment of a metal-processing facility calls for a heavy-duty industrial analyzer, and to guarantee accurate hydrogen readings, that analyzer must be field-calibratable.

Solution

The Panametrics XMTCpro thermal conductivity analyzer, built into a sample conditioning system, continuously measures the hydrogen percentage in the furnace atmosphere and transmits the reading to the plant’s data acquisition and control system. XMTCpro exploits the difference in thermal conductivity between hydrogen and the background gas – it has no moving parts and does not rely on any chemical reaction or gas adsorption. The analyzer is supplied with a display/controller that can be programmed to run the calibration routine automatically at a predetermined time, keeping the measurement accurate with minimal operator intervention.

Panametrics XMTCpro thermal conductivity analyzer

Datasheet (PDF) Panametrics XMTCpro

Source: Panametrics Application Note PANA050AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, official Panametrics representative for Slovakia and Hungary.

2. September 2026 by Bohuslav Bobrik Bohuslav Bobrik

Hydrogen Purity Measurement Ensures Safe and Efficient Operation of Hydrogen-Cooled Generators

APPLICATION NOTE

Hydrogen Purity Measurement Ensures Safe and Efficient Operation of Hydrogen-Cooled Generators

Problem

Hydrogen is used as the cooling medium in large electricity generators due to its high thermal conductivity and low viscosity, which prevents efficiency losses from increased drag or windage on the rotor. The high rotational speed of large diameter rotors generates heat, so the rotor side of the generator set requires high rates of cooling at low drag for efficiency. The hydrogen is pumped from the generator into a closed drier and cooling system before re-entering the generator. Contamination with air must be avoided to mitigate the risk of explosion, prevent early failure of mechanical components, and reduce inefficiency. A reduction in hydrogen purity from 97% to 95%, for example, can increase windage losses by as much as 32%. Removing oxygen also reduces the potential for damage to the winding insulation caused by corona discharges.

Application

Regular operation	80% – 100% H₂ in air
Purging	0% – 100% air in CO₂
Scavenging	0% – 100% CO₂ in H₂

Benefits:

Highly robust analyzer capable of measuring all required ranges, with high reliability driven by having no moving parts and proven industry references
Turnkey solution with full sample handling capabilities
Simple field calibration

Challenge

The challenge for the customer is to ensure that their closed-loop hydrogen system has an accurate and reliable measurement of hydrogen purity so that the safety and efficiency of the generator set is maintained. While customers typically measure hydrogen leaks to atmosphere outside the generator with ambient monitors, the primary measurement is on the purity within the closed-loop system. During regular maintenance intervals, there is also a requirement to enter the generator housing and vent it to atmosphere. To avoid the risk of explosion from mixing hydrogen with air, a scavenging system is used to first displace the hydrogen with an inert gas such as CO₂. Only when measurement confirms that the hydrogen has been displaced is the CO₂ in turn displaced with air, and only once measurement confirms that air is present can maintenance be safely carried out.

Solution

The Panametrics XMTCpro thermal conductivity analyzer is perfect for this application. This solution has the added advantage of being able to measure the two other gas ranges during start-up purging and shut-down scavenging. During start-up, the XMTCpro is set to measure air in CO₂. When the analyzer confirms a full CO₂ atmosphere, hydrogen is introduced and the XMTCpro is set to measure H₂ in CO₂. Once full displacement has been achieved, the analyzer is set to measure air in hydrogen. For shut-down, the process is reversed, and the XMTCpro analyzer again measures and confirms the scavenging of the relevant gases.

Panametrics XMTCpro Thermal Conductivity Analyzer

Datasheet (PDF) Panametrics XMTCpro

Source: Panametrics Application Note PANA051AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, the official Panametrics representative in Slovakia and Hungary.

2. September 2026 by Bohuslav Bobrik Bohuslav Bobrik

Oxygen Measurement in Reactor Feed Gas Ensures Reliable Formaldehyde Production

APPLICATION NOTE

Panametrics XMO2pro – oxygen measurement in reactor feed gas

Oxygen Measurement in Reactor Feed Gas Ensures Reliable Formaldehyde Production

Problem

Oxygen is commonly measured in reactor feed gases or reactor head spaces. One such application is the industrial production of formaldehyde. Formaldehyde is produced by mixing specific amounts of methanol vapor with oxygen in a reactor in the presence of a catalyst, most commonly metal oxides. This method keeps the methanol vapor below the explosive limit that would be surpassed by more traditional techniques using a silver catalyst. With 80% of the production cost of formaldehyde being made up of the raw material used in the reaction, the oxygen content within the reactor must be controlled at an optimum level to produce a successful yield.

Application

Application	0% to 21% O₂ in N₂ saturated with methanol vapors
Temperature	Ambient
Pressure	5 psig (≈0.34 bar)

Benefits:

No moving parts to be fouled by liquid carryover
Sensor is not consumed as with galvanic fuel cells
Simple field calibration
Turnkey sample conditioning system

Challenge

The challenge in this application relates to the potential for liquid carryover to the oxygen analyzer, along with the reliability of the measurement. Traditional dumbbell-type paramagnetic sensors have been used in the past for these applications; however, they required extensive maintenance. Liquid carryover is extremely damaging to these units, so the challenge is to use an oxygen analyzer with minimal maintenance requirements and the durability to recover from process upsets.

Solution

Air is used as the source of oxygen in the formaldehyde production process. The air and methanol vapor mixture is sampled at the inlet to the reactor. The XMO2pro thermoparamagnetic oxygen transmitter verifies that the optimal amount of oxygen — typically 9.8% — is present to achieve a complete reaction with minimal waste. The sample system is mounted near the sample point to prevent measurement lag time. A typical installation includes the thermoparamagnetic oxygen transmitter, a display/controller and a sample system. The sample system components — including the inlet and calibration valves, a filter/coalescer assembly, pressure gauge and flowmeter — are normally plate-mounted.

Sample system diagram with XMO2pro oxygen analyzer

Panametrics XMO2pro Oxygen Analyzer

Datasheet (PDF) Panametrics XMO2pro

Source: Panametrics Application Note PANA059AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, the official Panametrics representative in Slovakia and Hungary.