Best Ammonia Gas Detectors (and Expert Tips)
An ammonia gas detector senses the concentration of ammonia (NH3) in the air. These devices are used for personal protection in hazardous gas environments. Poultry and swine farms use ammonia gas detectors to make sure the indoor air quality is safe for livestock. Gaseous ammonia is also present in many industrial processes. As NH3 gas leaks are very dangerous, continuous ammonia monitoring is required for worker safety.
What Is an Ammonia Gas Detector?
An ammonia gas detector is an instrument used to detect the concentration of ammonia in the air. These devices have a long-life battery, large screen that displays NH3 concentration, and a belt clip to connect to clothing. In order to protect users, ammonia gas detectors also have LED, vibration, and buzzer alarms.
Ammonia gas detector are also known as NH3 monitors, ammonia sniffers, ammonia analyzers, or ammonia gas testers. These names all refer to the same device, an ammonia gas detector.
What Does an Ammonia Meter Detect?
An ammonia detector senses ammonia (NH3) gas and displays the levels in parts per million (ppm).
What Is Ammonia Gas?
Ammonia has the chemical symbol NH3. It is a very useful yet dangerous gas.
When we are exposed to NH3, its corrosive nature burns our skin, eyes, and lungs. Inhaling ammonia gas is a major problem as it will irritate the throat, nose, and lungs.
Despite its harmful effects, ammonia is useful in many manufacturing processes. NH3 is used as a refrigerant, in fertilizers, and the creation of plastics, dyes, and textiles.
Ammonia gas has always been a challenge for poultry and swine (pig) farmers. For example, ammonia in a poultry house is directly produced by the chickens. Due to poor waste management, ammonia gas can accumulate to dangerous levels for both livestock and humans.
What Is Anhydrous Ammonia?
In Greek, anhydrous means "without water." Anhydrous ammonia is pure, compressed ammonia that is typically stored and transported in liquid form. This chemical also easily dissolves in water. When referring to anhydrous ammonia, it typically is:
- In liquid form.
- Contains no water in the ammonia liquid (i.e. pure form of ammonia).
- Compressed, stored, and transported in tanks.
- Used as a nitrogen fertilizer. Anhydrous ammonia is applied directly to soil in corn fields. The below image shows a tractor with an anhydrous fertilizer applicator attached. By towing the anhydrous ammonia supply tank behind it, the vehicle constantly applies ammonia to the corn field.
Can I Smell Ammonia Gas?
Yes, humans can smell ammonia gas.
However, the odor threshold can vary from person to person.
- An academic study showed that the mean odor detection threshold was 2.6 ppm.
- A Japanese study showed an odor threshold of 1.5 ppm.
- Another study found the ammonia odor threshold within a concentration range of 1.1 – 1.5 ppm.
- OSHA mentions that the ammonia odor threshold is around 5ppm.
In general, it is a bad idea to depend on your sense of smell to determine the "potency" of an aromatic gas like ammonia. This is because your nose will become less sensitive to the odor as you get used to it.
This phenomenon is called olfactory fatigue. This is when the nose adapts, becoming blind to the odor. Other "aromatic" gases such as ozone also causes this effect. After a prolonged period of exposure, your sense of smell becomes less sensitive to the particular odor.
What Are the Different Types of Ammonia Detectors?
Ammonia Detector for Air Quality (Farms, Indoor or Outdoor)
These are handheld ammonia gas detectors used to check air quality in poultry houses and indoor livestock facilities. Easy to use with a large screen showing the ammonia ppm concentration.
Ammonia Detector for Personal Protection
The majority of Ammonia gas detectors are portable. These are small, battery-powered units with an NH3 sensor that can be clipped onto your clothes. Portable detectors provide continuous protection with LED, buzzer, and vibration alarms.
Ammonia Wall Mount Monitor
Fixed, wall-mounted units provide continuous protection. These devices are perfect for an indoor poultry farm. If the levels of ammonia pass the preset threshold, the unit will alarm and automatically trigger the ventilation system.
How Does an Ammonia Gas Sensor Work?
An ammonia gas detector is made up of electronics and an NH3 sensor. The gas sensor converts the detected gas concentration to an electronic signal for analysis by the onboard microprocessor. After receiving a signal, the processor displays the reading. If the measurement exceeds the pre-set alarm value, the alarms will be triggered to warn the user.
The gas reacts with a working electrode, triggering an electrochemical redox reaction. The generated current is proportional to the detected gas level.
What Are Safe Ammonia Gas Levels?
Various government agencies and associations have recommended gas exposure limits, examples can be seen below.
Recommendation / Requirement
National Institute for Occupational Safety and Health (NIOSH)
NIOSH Recommended Exposure Limit (REL):
25 ppm, 10 hour TWA
35 ppm, 10-minute ceiling
Occupational Safety and Health (OSHA)
50 ppm average over 8 hours
American Conference of Governmental Industrial Hygienists (ACGIH)
25 ppm average over 8 hours
35 ppm (Short Term Exposure Limit - STEL)
Is Ammonia Detection Used for Poultry Farms?
Yes it is. Poultry farmers are some of the most common customers of ammonia detectors. These devices help keep ammonia gas levels low to sustain healthy livestock and produce maximum yield for farms.
Measuring ammonia in farms and other indoor livestock facilities have additional benefits for farmers. NH3 detection is necessary to improve waste management, ensure proper ventilation and air flow, and control protein feed regiments.
What Is an Ammonia Detector Used For?
Ammonia is used in a plethora of manufacturing and industrial processes. In some cases, it is very important to detect any ammonia to protect employee health.
Ammonia as a Fertilizer
Ammonia is applied to the earth as a fertilizer that helps increase yields of crops, such as maize and wheat.
Ammonia as a Cleaner
Used in household cleaning agents and window cleaners. It has a streak-free shine, making it perfect for windows. Household cleaners range in concentration by weight from 5 - 10% ammonia.
Ammonia in Industry
Used as a precursor to derive nitrogen-based compounds. Nearly all synthetic nitrogen compounds are derived from ammonia. An important derivative of the chemical is nitric acid.
Ammonia in Farms
Ammonia is generated from livestock waste, which irritates the livestock and negatively impacts yield.
Can an Ammonia Detector Be Used to Detect a Sewer Gas Leak?
No, we do not recommend using an ammonia detector for suspected gas leaks in pipes, joints, or appliances. As a first step, it is better and more cost-effective to use a gas leak detector with gooseneck, semiconducting metal oxide sensor, and ppm reading. See here.
What Is the Best Ammonia Detector?
There are many ammonia gas detectors on the market. The reputable brands include the following:
- Forensics Detectors Ammonia Detectors
- MSA NH3 Monitors
- RKI Portable NH3 Detectors
- Industrial Scientific NH3 Monitors
- Draeger NH3 Meters
- Sensidyne NH3 Detectors
How Do I Select an Ammonia Sensor?
To select the best ammonia gas detector for your needs, follow this guide. Start thinking about these questions to narrow down your options:
- Do I need a probe with the unit? Do I need to sample from a specific point or am I using it for personal protection?
- What is my budget and operating cost budget?
- Do I need advanced functions such as data-logging or Bluetooth?
- Do I need specific accreditations with the monitor such as ATEX or a NIST traceability calibration certificate?
- Do I require a belt clip for attaching the device to my clothes?
- Do I need after-sales support, USA headquarters, or fast calibration services?
How Long Does an Ammonia Sensor Last For?
Ammonia detectors incorporate small electrochemical sensors that usually last between 24 and 36 months.
How Do I Test My Ammonia Detector?
The best way to test your ammonia gas detector is to expose it to a known gas source. Generally referred to as bump testing, this is a good practice to perform daily. Frequent testing is especially important in personal protection applications where safety is paramount - more about bump testing in the next section.
What Is an Ammonia Detector Bump Test?
- Bump testing is a procedure where the user exposes the detector to a small amount of “blast” target gas to ensure the detector operates and alarms as programmed.
- The function of this test is to verify proper operation and build user confidence, particularly in hazardous applications.
- It is recommended to bump test when first purchased, with subsequent testing every week. If using in LIFE-THREATENING and / or DANGEROUS applications, bump test daily.
- Ammonia bump test gas can be found here.
- Tip: Spray Windex on a cloth. Place it over the sensor of your ammonia gas detector. The ammonia from the cleaner will trigger a bump test response.
What Is Ammonia Detector Gas Calibration?
Ammonia gas detector calibration is the technical task of adjusting the detector to a more accurate gas reading. Over time, the sensors on the device will degrade or produce drifting readings. We suggest calibrating your ammonia detector every 6 to 12 months, the typical time period for gas detectors.
Gas calibration is a technical task that requires certain key pieces of equipment. These include a calibration gas bottle, gas regulator, tubing, and calibration cap fitting. You need to communicate with the manufacturer to determine the recommended calibration gas concentrations and mixtures. For the Forensics Detectors ammonia gas monitors, we recommend gas calibration with ammonia gas at 50ppm. See ammonia calibration gas here.
Be attentive and calibrate daily if:
- The user employs the device as an analytical tool where accuracy is paramount.
- The device is used in an extreme environment (temp and humidity extremes create sensor drift).
- The user is performing an imminently dangerous application.
- Bump testing fails. In this case, you must calibrate to make sure the sensors and monitor operate properly.
- The ammonia gas detector alarms in the fresh air. This could mean that the sensor has drifted past an alarm set-point.
Calibration and bump testing are mandatory because injury or death can occur if the device fails. Take it very seriously.
Also, it is prudent to have a calibration schedule that the owner or employees strictly follow. See gas calibration here.
How Do I Properly Use an NH3 Gas Detector?
When operating an ammonia gas detector, there are some important tips to consider. After reading your product manual, be sure to keep these tips in mind:
- Turn ON the ammonia gas monitor in the fresh air.
- Ensure the ammonia gas monitor is within its calibration period.
- Ensure the ammonia gas monitor has been bump tested and validated as operational.
- Check the alarm set-points. Set your alarms as desired (some units may not have adjustable alarms).
- If performing analytical measurements, keep the unit stationary. Ensure humidity and temperature are also tracked and are as constant as possible.
- If using a pump, turning the pump ON/OFF will change the pressure and may effect readings. Take data point readings when the pump is either off or on after 60 seconds, so the "pressure change" does not cause false data points.
Is Ammonia Gas Explosive?
Yes, ammonia is flammable at concentrations from 15 - 28% in air.
Therefore, ammonia gas has a lower explosive limit (LEL) of 15% - this means it is too lean to burn.
The upper explosive limits (UEL) of 28% means it is too rich to burn.
- An ammonia gas detector senses ammonia (NH3) gas concentration in air. It is a toxic gas - OSHA 8 hour recommended TWA is 50 ppm.
- Most useful for personal protection in hazardous gas environments.
- The largest market for ammonia detectors is the poultry and swine markets. Detectors are used to check indoor air quality for improved livestock health and employee safety.
- Ammonia gas is also used in many industrial processes. An NH3 gas leak is very dangerous, so continuous ammonia monitoring may be required in certain settings.
About The Author
Dr. Koz is the President of FORENSICS DETECTORS, where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters, and gas analyzers. He has been designing, building, manufacturing, and testing toxic gas detection systems for over 20 years.
Every day is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers, and having a cold beer.
Read more about Forensics Detectors here.