Ammonia (NH3) sensors

Ammonia is a colorless, pungent gas that is widely used in many industrial applications and found in agricultural production. It is a critical component in the manufacture of fertilizers, plastics, and explosives, among other things. However, ammonia can be hazardous to human and animal health and the environment when it is released into the atmosphere. As such, the need for accurate and reliable ammonia measurement sensors has become increasingly important in recent years.

Types of Ammonia Measurement Sensors

There are several types of ammonia measurement sensors available in the market, and each one operates on a different principle. Some of the most common ammonia measurement sensors include:

1. Electrochemical sensors
2. Metal-oxide sensors
3. Photoionization detectors
4. Infrared sensors
5. Catalytic sensors

Electrochemical Ammonia Sensors

Electrochemical sensors are among the most widely used ammonia measurement sensors. These sensors operate by measuring the current produced when ammonia reacts with a sensing electrode. The magnitude of the current is proportional to the concentration of ammonia in the air. The sensor’s sensitivity can be adjusted by changing the composition of the sensing electrode, and the measurement range can be customized to meet specific application requirements.

Metal-Oxide Sensors

Metal-oxide sensors operate by detecting changes in the electrical conductivity of a metal oxide film when it comes into contact with ammonia. The metal oxide film is typically made of tin oxide, and the sensor’s sensitivity can be adjusted by varying the thickness of the film or the operating temperature. Metal-oxide sensors are highly sensitive and can detect ammonia at concentrations as low as a few parts per billion.

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Ammonia Sensor for Poultry

Ammonia is one of the most common causes of low animal welfare in chicken farms. It is also a major cause of respiratory problems, sores on feet and breasts as well as lower gain.

What is Ammonia?

Ammonia is a chemical compound between the elements nitrogen (N) and hydrogen (H), and has the formula NH3. The substance is found everywhere in nature and occurs naturally in manure and urine.

The smell of ammonia is known, among other things, from the pungent smell of manure or in the environment of a chicken farm.

Ammonia is formed in humans and animals by the breakdown of proteins (albumin) from the diet, or in connection with the ongoing remodeling of all tissues in the body. A part is also formed in the intestine from the breakdown of proteins and other nitrogenous compounds by bacteria.

Ammonia in Poultry Houses

In poultry houses ammonia is a byproducts of manure. When nitrogen compounds are decomposed the result is formation of ammonia (NH3+) and ammonium (NH4-). Ammonia is lighter than air and therefor it floats into the air causing respiration problems and bad smell. Ammonia formation is nurtured by low pH in the litter, high temperatures, and high humidity inside the poultry house.

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Ammonia (NH₃) is one of the most significant environmental and welfare challenges in modern pig production. While it is a natural by-product of livestock systems, excessive ammonia emissions can negatively affect animal health, worker safety, and the surrounding environment. Understanding how ammonia is produced — and how it can be managed — is essential for sustainable, efficient pig farming.

What Is Ammonia and How Is It Produced?

In pig production, ammonia is primarily formed when urea and uric acid in manure and urine are broken down by bacteria. The enzyme urease, naturally present in feces, catalyzes this conversion, releasing ammonia gas into the air.

Key factors influencing ammonia formation include:

• Temperature: Higher temperatures accelerate bacterial activity and volatilization.
• pH: Ammonia release increases when manure pH is above 7.5.
• Ventilation: Inadequate ventilation allows ammonia to accumulate in barns.
• Manure management: Frequent removal and cooling of manure reduce emissions.

Learn more about the benefits of automated climate and ventilation in pig production.

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Impacts of Ammonia in Pig Housing

1. Animal Health and Welfare

High concentrations of ammonia irritate the pigs’ respiratory tract, leading to:

• Reduced lung function and increased susceptibility to respiratory diseases.
• Lower feed intake and growth rates.
• Increased stress and reduced overall welfare.

Concentrations above 20 ppm are considered harmful to pigs, and levels above 10 ppm are generally discouraged in modern facilities.

2. Worker Health

Ammonia exposure can cause eye and throat irritation, headaches, and long-term respiratory problems in farm workers. Maintaining clean air is therefore not only an animal welfare priority but also a matter of occupational safety.

3. Environmental Impact

Once emitted into the atmosphere, ammonia contributes to acid rain among other things. This has downstream effects on soil, water quality, and climate. The pig industry and other industries are under increasing regulatory pressure to reduce ammonia emissions as part of broader sustainability goals.

4. Production Performance and Efficiency

Ammonia doesn’t just affect welfare — it has a direct impact on productivity. Chronic exposure to elevated ammonia levels has been shown to:

• Reduce average daily gain (ADG) and feed conversion efficiency (FCR).
• Delay the time to reach market weight, increasing feed costs per kilogram of gain.
• Lead to uneven growth within groups, complicating management and marketing.

Studies indicate that pigs exposed to ammonia concentrations above 25–30 ppm may experience growth rate reductions of 5–10%, depending on duration and housing conditions. Maintaining low ammonia levels therefore supports both animal health and economic performance.

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