Description
Ammonia (NH3) is a colourless gas with a characteristic pungent, suffocating odour. It is highly soluble in water and is often encountered as an aqueous solution (e.g., household ammonia). While naturally occurring and essential for biological processes, it is also widely used in industry and can be hazardous in concentrated forms or in poorly ventilated areas.
Key Properties
- Colourless: Invisible to the naked eye.
- Pungent, Suffocating Odour: Strong, distinctive smell, even at low concentrations. This serves as a warning, but can also cause “olfactory fatigue” at high concentrations, making it harder to detect.
- Highly Soluble in Water: Forms ammonium hydroxide when dissolved in water, which is a corrosive alkaline solution.
- Lighter than Air: Tends to rise and disperse, but can accumulate in enclosed spaces.
- Corrosive/Irritating: Irritates eyes, skin, and respiratory tract.
Replacement Sensor, Part No. 17124975-6, Properties
| Gas Detected (Abbreviation) |
Type | Measurement | Response time (Seconds) |
Calibration Gas & Concentration |
||
|---|---|---|---|---|---|---|
| Range | Resolution | T50 | T90 | |||
| Ammonia (NH3) |
Electrochemical | 0 to 500 ppm | 1.0 ppm | 21 | 78 | NH3 50 ppm |
Sensor may become unstable, if the battery is removed from the instrument or after the low battery warning is activated. If either incidence occurs, change the battery (or re-install the existing battery if it has suitable life remaining), then power the monitor ON then OFF, and allow at least 24 hours for the sensors to stabilise.
Toxic Gas Sensor Cross-sensitivity Table
| Target Gas | Sensor | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CO | CO (H2 Low) |
H2S | SO2 | NO2 | Cl2 | ClO2 | HCN | HCl | PH3 | NO | H2 | NH3 | |
| CO | 100 | 100 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 20 | 0 |
| H2S | 5 | 5 | 100 | 1 | -40 | -3 | -25 | 10 | 300 | 25 | 10 | 20 | 25 |
| SO2 | 0 | 5 | 5 | 100 | 0 | 0 | 0 | – | 40 | – | 0 | 0 | -40 |
| NO2 | -5 | 5 | -25 | -165 | 100 | 45 | – | -70 | – | – | 30 | 0 | -10 |
| Cl2 | -10 | 0 | -20 | -25 | 10 | 100 | 60 | -20 | 6 | -20 | 0 | 0 | -50 |
| ClO2 | – | – | – | – | 20 | 100 | – | – | – | – | – | – | – |
| HCN | 15 | – | – | 50 | 1 | 0 | 0 | 100 | 35 | 1 | 0 | 30 | 5 |
| HCl | 3 | – | – | 5 | 0 | 2 | 0 | 0 | 100 | 0 | 15 | 0 | 0 |
| PH3 | – | – | – | – | – | – | -100 | 425 | 300 | 100 | – | – | – |
| NO | 25 | 40 | -0.2 | 1 | 5 | – | – | -5 | – | – | 100 | 30 | 0 |
| H2 | 22 | 3 | 0.08 | 0.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 100 | 0 |
| NH3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 100 |
The table above reflects the percentage response provided by the sensor (top row) when exposed to a known concentration of the target gas (column 1).
The numbers were measured under these environmental conditions: 20 °C (68 °F), 50% RH and 1 atm.
The specified cross-interference numbers apply to new sensors only and may vary with time as well as from sensor to sensor.
“-” means no data available.
This table is given as a reference only and is subject to change.
