Hydrogen sulfide is the chemical compound with the formula H2S. It is a colorless chalcogen hydride gas with the characteristic foul odor of rotten eggs. It is very poisonous, corrosive, and flammable.
Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen gas, such as in swamps and sewers; this process is commonly known as anaerobic digestion which is done by sulfate-reducing microorganisms. H2S also occurs in volcanic gases, natural gas, and in some sources of well water. [1]
Hydrogen sulfide is a broad-spectrum poison, meaning that it can poison several different systems in the body, although the nervous system is most affected. The toxicity of H2S is comparable with that of carbon monoxide. It binds with iron in the mitochondrial cytochrome enzymes, thus preventing cellular respiration. Since hydrogen sulfide occurs naturally in the body, the environment, and the gut, enzymes exist to detoxify it. At some threshold level, believed to average around 300–350 ppm, the oxidative enzymes become overwhelmed. Many personal safety gas detectors, such as those used by utility, sewage and petrochemical workers, are set to alarm at as low as 5 to 10 ppm and to go into high alarm at 15 ppm. Detoxification is effected by oxidation to sulfate, which is harmless. Hence, low levels of hydrogen sulfide may be tolerated indefinitely.
Exposure to lower concentrations can result in eye irritation, a sore throat and cough, nausea, shortness of breath, and fluid in the lungs (pulmonary edema). These effects are believed to be due to the fact that hydrogen sulfide combines with alkali present in moist surface tissues to form sodium sulfide, a caustic. These symptoms usually go away in a few weeks.
Long-term, low-level exposure may result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness. Chronic exposure to low level H2S (around 2 ppm) has been implicated in increased miscarriage and reproductive health issues among Russian and Finnish wood pulp workers, but the reports have not (as of circa 1995) been replicated.
Short-term, high-level exposure can induce immediate collapse, with loss of breathing and a high probability of death. If death does not occur, high exposure to hydrogen sulfide can lead to cortical pseudolaminar necrosis, degeneration of the basal ganglia and cerebral edema. Although respiratory paralysis may be immediate, it can also be delayed up to 72 hours.

0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it.

10 ppm is the OSHA permissible exposure limit (PEL) (8 hour time-weighted average).

10–20 ppm is the borderline concentration for eye irritation.

20 ppm is the acceptable ceiling concentration established by OSHA.

50 ppm is the acceptable maximum peak above the ceiling concentration for an 8-hour shift, with a maximum duration of 10 minutes.

50–100 ppm leads to eye damage.

At 100–150 ppm the olfactory nerve is paralyzed after a few inhalations, and the sense of smell disappears, often together with awareness of danger.

320–530 ppm leads to pulmonary edema with the possibility of death.

530–1000 ppm causes strong stimulation of the central nervous system and rapid breathing, leading to loss of breathing.

800 ppm is the lethal concentration for 50% of humans for 5 minutes' exposure (LC50)

Concentrations over 1000 ppm cause immediate collapse with loss of breathing, even after inhalation of a single breath.

Carbon monoxide (CO) is a colorless, odorless, and tasteless flammable gas that is slightly less dense than air. It is toxic to animals that use hemoglobin as an oxygen carrier (both Invertebrate and vertebrate) when encountered in concentrations above about 35 ppm, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions. In the atmosphere, it is spatially variable and short lived, having a role in the formation of ground-level ozone.[2] Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries. Carbon monoxide is colorless, odorless, and tasteless, but highly toxic. It combines with hemoglobin to produce carboxyhemoglobin, which usurps the space in hemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. Concentrations as low as 667 ppm may cause up to 50% of the body's hemoglobin to convert to carboxyhemoglobin. A level of 50% carboxyhemoglobin may result in seizure, coma, and fatality. In the United States, the OSHA limits long-term workplace exposure levels above 50 ppm.
The most common symptoms of carbon monoxide poisoning may resemble other types of poisonings and infections, including symptoms such as headache, nausea, vomiting, dizziness, fatigue, and a feeling of weakness. Affected families often believe they are victims of food poisoning. Infants may be irritable and feed poorly. Neurological signs include confusion, disorientation, visual disturbance, syncope (fainting), and seizures.
Some descriptions of carbon monoxide poisoning include retinal hemorrhages, and an abnormal cherry-red blood hue. In most clinical diagnoses these signs are seldom noticed. One difficulty with the usefulness of this cherry-red effect is that it corrects, or masks, what would otherwise be an unhealthy appearance, since the chief effect of removing deoxygenated hemoglobin is to make an asphyxiated person appear more normal, or a dead person appear more lifelike, similar to the effect of red colorants in embalming fluid. The "false" or unphysiologic red-coloring effect in anoxic CO-poisoned tissue is related to the meat-coloring commercial use of carbon monoxide, discussed below.
Carbon monoxide also binds to other molecules such as myoglobin and mitochondrial cytochrome oxidase. Exposures to carbon monoxide may cause significant damage to the heart and central nervous system, especially to the globus pallidus, often with long-term chronic pathological conditions. Carbon monoxide may have severe adverse effects on the fetus of a pregnant woman.

[1] Hydrogen sulfide
[2] Carbon monoxide

SMOGGIE-GAS is designed as an automated, fixed, Air Quality monitoring station that measures and reports the target gas concentration automatically, 24/7. It comes with built-in Wifi connectivity and it only needs 5V to run, supplied via a standard micro-USB cable. It will monitor your location 24/7 to inform you on elevated GAS levels that can impact your health. Each SMOGGIE-GAS comes with one electrochemical sensor to measure H2S, O3, NO2, SO2 or CO. You can choose the gas at checkout.
The units can be managed via the dashboard. The data can be viewed remotely on a computer or on a mobile device. Picture: uRADMonitor SMOGGIE motherboard and enclosure

Item	Parameter	Ratings
Voltage	External	5V micro-USB
Consumption	Current	80mA
Connectivity	Internet	Wifi
Microcontroller	ESP8266	8 bit
Enclosure	Rainproof plastic	42x43x47 mm

Your uRADMonitor unit can be mounted both indoors and outdoors where the enclosure offers protection against sun, rain or snow. The unit has a plastic enclosure with two holes and can be easily attached to a wall with only two screws. The sensor opening must face down for open air access. Make sure that nothing is blocking the air vents. The openings and the internal heating of the electronics are aligned to generate an active airflow.
Quick Setup
Connect it to power using a 5V micro-USB cable. Use a smartphone or a computer with WLAN capabilities to connect to the local hotspot spawned by your SMOGGIE unit. The SSID is uRADMonitor-XX, where XX are the last two digits of the Device ID number. The key is the Device ID, in uppercase, as printed on the enclosure. You can change this key later. Open 192.168.4.1 in your browser, and click the "WIFI/CONFIG" link to setup the connection to the Internet AP. Select the SSID and enter the key of your Internet Access Point.
Picture: SMOGGIE Config Page If the connection fails, you will see the status message.
USB configuration
Alternatively, the SSID and KEY can also be configured via USB. Connect to your SMOGGIE via USB, baudrate 9600bps, open a terminal program and type the two commands: "key1","SSID" then "key2","your WLAN key" . Use the "getsettings" command to verify that the new settings are in place. Quotes are a must, and there are no spaces in between. See the USB Commands manual for more. See the USB Commands manual if you need more help.

Quick Start
Technical Datasheet
USB Serial Commands Manual
Product Limited Warranty terms
uRADMonitor with WIFI Configuration manual
Open source on Github

Data access:
Terms of Service
API Terms of Service
API and Server Specs
Direct Data access

USB Driver
In their recent versions, Windows, Linux and MacOS come with built in drivers for your uRADMonitor unit. Use the following resources only if the built in drivers do not work for you.
USB Driver for Windows
USB Driver for Linux
USB Driver for MacOS

RO:
RO: Ghid rapid de utilizare
RO: conditii generale de utilizare

Hydrogen sulfide is the chemical compound with the formula H2S. It is a colorless chalcogen hydride gas with the characteristic foul odor of rotten eggs. It is very poisonous, corrosive, and flammable.
Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen gas, such as in swamps and sewers; this process is commonly known as anaerobic digestion which is done by sulfate-reducing microorganisms. H2S also occurs in volcanic gases, natural gas, and in some sources of well water. [1]
Hydrogen sulfide is a broad-spectrum poison, meaning that it can poison several different systems in the body, although the nervous system is most affected. The toxicity of H2S is comparable with that of carbon monoxide. It binds with iron in the mitochondrial cytochrome enzymes, thus preventing cellular respiration. Since hydrogen sulfide occurs naturally in the body, the environment, and the gut, enzymes exist to detoxify it. At some threshold level, believed to average around 300–350 ppm, the oxidative enzymes become overwhelmed. Many personal safety gas detectors, such as those used by utility, sewage and petrochemical workers, are set to alarm at as low as 5 to 10 ppm and to go into high alarm at 15 ppm. Detoxification is effected by oxidation to sulfate, which is harmless. Hence, low levels of hydrogen sulfide may be tolerated indefinitely.
Exposure to lower concentrations can result in eye irritation, a sore throat and cough, nausea, shortness of breath, and fluid in the lungs (pulmonary edema). These effects are believed to be due to the fact that hydrogen sulfide combines with alkali present in moist surface tissues to form sodium sulfide, a caustic. These symptoms usually go away in a few weeks.
Long-term, low-level exposure may result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness. Chronic exposure to low level H2S (around 2 ppm) has been implicated in increased miscarriage and reproductive health issues among Russian and Finnish wood pulp workers, but the reports have not (as of circa 1995) been replicated.
Short-term, high-level exposure can induce immediate collapse, with loss of breathing and a high probability of death. If death does not occur, high exposure to hydrogen sulfide can lead to cortical pseudolaminar necrosis, degeneration of the basal ganglia and cerebral edema. Although respiratory paralysis may be immediate, it can also be delayed up to 72 hours.

0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it.

10 ppm is the OSHA permissible exposure limit (PEL) (8 hour time-weighted average).

10–20 ppm is the borderline concentration for eye irritation.

20 ppm is the acceptable ceiling concentration established by OSHA.

50 ppm is the acceptable maximum peak above the ceiling concentration for an 8-hour shift, with a maximum duration of 10 minutes.

50–100 ppm leads to eye damage.

At 100–150 ppm the olfactory nerve is paralyzed after a few inhalations, and the sense of smell disappears, often together with awareness of danger.

320–530 ppm leads to pulmonary edema with the possibility of death.

530–1000 ppm causes strong stimulation of the central nervous system and rapid breathing, leading to loss of breathing.

800 ppm is the lethal concentration for 50% of humans for 5 minutes' exposure (LC50)

Concentrations over 1000 ppm cause immediate collapse with loss of breathing, even after inhalation of a single breath.

Carbon monoxide (CO) is a colorless, odorless, and tasteless flammable gas that is slightly less dense than air. It is toxic to animals that use hemoglobin as an oxygen carrier (both Invertebrate and vertebrate) when encountered in concentrations above about 35 ppm, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions. In the atmosphere, it is spatially variable and short lived, having a role in the formation of ground-level ozone.[2] Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries. Carbon monoxide is colorless, odorless, and tasteless, but highly toxic. It combines with hemoglobin to produce carboxyhemoglobin, which usurps the space in hemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. Concentrations as low as 667 ppm may cause up to 50% of the body's hemoglobin to convert to carboxyhemoglobin. A level of 50% carboxyhemoglobin may result in seizure, coma, and fatality. In the United States, the OSHA limits long-term workplace exposure levels above 50 ppm.
The most common symptoms of carbon monoxide poisoning may resemble other types of poisonings and infections, including symptoms such as headache, nausea, vomiting, dizziness, fatigue, and a feeling of weakness. Affected families often believe they are victims of food poisoning. Infants may be irritable and feed poorly. Neurological signs include confusion, disorientation, visual disturbance, syncope (fainting), and seizures.
Some descriptions of carbon monoxide poisoning include retinal hemorrhages, and an abnormal cherry-red blood hue. In most clinical diagnoses these signs are seldom noticed. One difficulty with the usefulness of this cherry-red effect is that it corrects, or masks, what would otherwise be an unhealthy appearance, since the chief effect of removing deoxygenated hemoglobin is to make an asphyxiated person appear more normal, or a dead person appear more lifelike, similar to the effect of red colorants in embalming fluid. The "false" or unphysiologic red-coloring effect in anoxic CO-poisoned tissue is related to the meat-coloring commercial use of carbon monoxide, discussed below.
Carbon monoxide also binds to other molecules such as myoglobin and mitochondrial cytochrome oxidase. Exposures to carbon monoxide may cause significant damage to the heart and central nervous system, especially to the globus pallidus, often with long-term chronic pathological conditions. Carbon monoxide may have severe adverse effects on the fetus of a pregnant woman.

[1] Hydrogen sulfide
[2] Carbon monoxide

SENSIGAS is designed to detect very low concentrations of toxic gases. It does this by using a high volume electrochemical sensor with enhanced stability and response. As an automated, fixed, Air Quality monitoring station that measures and reports the target gas concentration automatically, 24/7. It comes with built-in Wifi connectivity and it only needs 5V to run, supplied via a standard micro-USB cable. It will monitor your location 24/7 to inform you on elevated GAS levels that can impact your health. Each sensor comes with one electrochemical sensor to measure the gas you select at purchase time (H2S, O3, NO2, SO2 or CO). You can choose the gas at checkout.
The units can be managed via the dashboard. The data can be viewed remotely on a computer or on a mobile device.

Item	Parameter	Ratings
Voltage	External	5V micro-USB
Consumption	Current	80mA
Connectivity	Internet	Wifi
Microcontroller	ESP8266	8 bit
Size and weight	Rainproof plastic	57x44 (64 with brackets)x 60mm and 125grams

Your uRADMonitor unit can be mounted both indoors and outdoors where the enclosure offers protection against sun, rain or snow. The unit has a plastic enclosure with two holes and can be easily attached to a wall with only two screws. The sensor opening must face down for open air access. Make sure that nothing is blocking the air vents. The openings and the internal heating of the electronics are aligned to generate an active airflow.
Quick Setup
Connect it to power using a 5V micro-USB cable. Use a smartphone or a computer with WLAN capabilities to connect to the local hotspot spawned by your SENSIGAS unit. The SSID is uRADMonitor-XX, where XX are the last two digits of the Device ID number. The key is the Device ID, in uppercase, as printed on the enclosure. You can change this key later. Open 192.168.4.1 in your browser, and click the "WIFI/CONFIG" link to setup the connection to the Internet AP. Select the SSID and enter the key of your Internet Access Point.
Picture: SENSIGAS Config Page If the connection fails, you will see the status message.
USB configuration
Alternatively, the SSID and KEY can also be configured via USB. Connect to your SENSIGAS via USB, baudrate 9600bps, open a terminal program and type the two commands: "key1","SSID" then "key2","your WLAN key" . Use the "getsettings" command to verify that the new settings are in place. Quotes are a must, and there are no spaces in between. See the USB Commands manual for more. See the USB Commands manual if you need more help.

Quick Start
Technical Datasheet
USB Serial Commands Manual
Product Limited Warranty terms
uRADMonitor with WIFI Configuration manual
Open source on Github

Data access:
Terms of Service
API Terms of Service
API and Server Specs
Direct Data access

USB Driver
In their recent versions, Windows, Linux and MacOS come with built in drivers for your uRADMonitor unit. Use the following resources only if the built in drivers do not work for you.
USB Driver for Windows
USB Driver for Linux
USB Driver for MacOS

RO:
RO: Ghid rapid de utilizare
RO: conditii generale de utilizare