Gas Leak Detectors, Monitor Sensor Selection Guide

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Gas Leak Detectors

Minimize Health Risks with a Gas Leak Detector


More people are choosing to use natural gas in their homes or their boats , particularly in the wake of increasing electricity costs. Anyone who has natural gas needs to invest in a gas leak detector for his or her safety.

By introducing technology "Blue Gas Marine Inc." Company makes natural gas boating a reality. The BG company, headquartered in Apex, Carolina is dedicated to make natural gas available for boats, as a clean and affordable fuel. This company also makes the fuel available where boaters need it.

Positive Impact Now

This innovation will also positively impact the marine industry and boaters in general by meeting and exceeding the regulatory requirements of upcoming emissions law, for certain displacement-size engines, hybrid and dedicated systems ahead of the stringent regulations coming into effect in 2015, 2016 and 2017, which require cleaner operations.

Durable and reliable the GasAlertClip Extreme by "BW Technologies by Honeywell" offers continuous, reliable protection for ships and boats and this single unit requires no calibration.

Gas Detector

This one of the most cost-effective "PPE solutions", also Water-resistant and Low cost gas detector for facility workers and on-site contractors.

Dangers

Also one boat or yacht maybe has a natural gas (NG) set up for the stove. But Is it safe and Is it readily available in marinas when it comes time to refill?

There are dangers associated with natural gas use. The methane that it contains is both toxic and flammable. A small leak will result in dizziness, fatigue, nausea, irregular breathing, loss of consciousness and possibly death if inhaled. Gas that accumulates in the air can lead to an explosion or a fire.

Because natural gas has no odor, the gas companies usually add a compound that contains sulfur. This gives the natural gas a rotten egg smell to indicate when there is a leak. Gas leak detectors, however, are more reliable and offer better protection than your nose.

Gas leak detectors typically use infrared gas detectors to find leaks that can easily come from pipes, appliances or heating systems. The infrared detectors absorb the infrared radiation of natural gas and measure the levels of radiation after converting it into an electrical signal. Gas leak detectors determine how much gas is present in the environment. When the levels become too high, the detector will trigger an alarm. When choosing a gas leak detector for your property, there are a few things that you need to keep in mind.

It is important to realize that certain gas leak detectors must be calibrated to ensure that you have accurate readings. Research different detectors and determine if they require calibrating. Find out how the calibration is done. Some calibrations may require the gas company or technicians to assist. It is important to have accurate readings, so do not ignore calibrating your detector.

LEL stands for the Lower Explosive Limit, which is the smallest amount of gas capable of causing an explosion. Different gas leak detectors have different LEL values. Some detect levels at 15 percent and others at 20 percent. Lower LEL values in gas leak detectors will detect gas and trigger an alarm faster than higher LEL values.

When installing your gas leak detector, it is important to place it in the correct location. They belong in areas where a leak is possible.

For example, place them near appliance, so that the alarm will signal quickly.

There are also different types of alarms available on gas leak detectors. You can find alarms that are both audible and visual, which offers added protection. Technicians mainly use portable detectors, and these vibrate when gas is detected.

Like any other device, you need to maintain your gas leak detector. Conduct regular checks using the test button. You should also replace the batteries so that you can be sure that they are completely charged.

Your needs will determine which type of gas leak detector you choose, as will the price. If you need one for your boat or home, you will have to find a detector that can be installed in areas where gas leaks are likely to occur.


You should also look for a detector that can pick up on propane as well as natural gas. On the other hand, technicians will require portable gas leak detectors that are able to pick up readings on different types of gas both inside and outside. Fortunately, there are a number of different gas leak detectors commercially available. Research the different options available to you, and make your decision based on your individual needs.

Sensors

Air Monitor Sensor Selection Guide


Check Facts to learn more about the importance of maintaining your air monitor!

There are many different combinations of sensors that may come with an air monitor. Single-gas air monitors have one sensor for detecting specific individual gases or they may have a combination of sensors to check for a variety of gases such as oxygen, chlorine, carbon monoxide, hydrogen sulfide, ammonia, methane and many others. The four sensors found most frequently are Oxygen, Combustible Gas (LEL sensor), Carbon Monoxide and Hydrogen Sulfide.

Air monitors, Marine Alarms & Detectors are very important pieces of equipment to your company and can often be life-saving; however, they can also often be overlooked.

This guide is intended to help you understand how sensor technology works in most portable gas monitors, and what you can do to maintain your air monitor so that it is working properly in emergency situations. This is a general guide and may not apply to your sensors. You should always refer to manufacturer’s guides for specific instructions on operating your air monitor.

a definite risk

In many work/services environments, there is a definite risk of illness, injury or even death from oxygen deficiency or toxic gases. However, these risks can be seriously reduced by using the gas detection technology in air monitors. In order to make sure that your air monitors and sensors are working properly you should always follow manufacturer's instructions regarding regular calibration, sensor replacement and "bump testing" your unit.

Sensor Construction

Oxygen and toxic sensors such as Carbon Monoxide and Hydrogen Sulfide are, for the most part, electrochemical sensors.

This means that a chemical reaction takes place inside the sensor causing an electrical current due to the flow of electrons. The electrical current is typically measured and displayed as a value in parts per million (ppm) for toxics and % volume for oxygen.

Guide to Carbon monoxide - Quickly finding, diagnosing, and fixing. Using A Combustion Analyzer Properly and Symptoms.

On board

Gas detectors and sensors can be powered by a self contained battery or be hard wired into a larger boat system, e.g. the simpler 12V or 24V DC boat wiring system.
Better types of gas detectors have remote sensors that can be placed in the areas where allow fitment of more than one sensor or gas vapours accumulate.

Oxygen sensor

An oxygen sensor is a consumable sensor, which means that it uses up something inside of the sensor when oxygen is present. In some oxygen sensors lead is converted to lead oxide when the chemical reaction takes place. Eventually all the lead will be used up and the sensor must be replaced. Even if the gas detector is turned off, the oxygen sensor is working. If the oxygen sensor is in air it is automatically detecting the level of oxygen and, therefore, its life is steadily decreasing.

Some manufacturers recommend disconnecting the sensor from the unit for a short period of time or storing it in an airtight container. However, if you remove the sensor, it may take anywhere from 15 minutes to 4 hours to warm up and give reliable readings again. These suggestions may only slightly extend the life of an oxygen sensor. They are typically warranted for one or two years, but most oxygen sensors last around two years.

Toxic sensor

A toxic sensor is non-consumptive, meaning that nothing inside the sensor is used up when it is exposed to its target gas.

A toxic sensor generally has a sensing electrode, a reference electrode, a counter electrode and a reservoir of an acid electrolyte (usually sulfuric or phosphoric). The sensing electrode detects gas coming into the sensor and, depending on the sensor, either oxidizes or reduces it. This reaction causes a rise or fall in the electrical potential of the sensing electrode in regards to the counter electrode.

The current that is created is in proportion to the gas level and generates a numerical value. Supposedly toxic sensors should last forever, but damage from contamination or leakage reduces the lifespan of these sensors. Most toxic sensors come with a two year warranty, but they typically last for over four years. Toxic sensors hold an acid electrolyte that can harm your instrument if there is a leak; waiting to replace an old sensor can lead to costly repairs.

Combustible sensors

Combustible sensors (LEL) are different from other sensors because they are not wet electrochemical reactors; rather they are solid state catalytic sensors. They consist of two porous ceramic beads surrounding a coiled wire. Each bead includes a catalyst system, one to make the first bead active and the other to make the second bead inert in order to use it as a source of reference.

While operating they draw a current to achieve an elevated temperature. This rise in temperature is due to the active bead burning any combustible gas it comes into contact with.

The temperature of the reference bead never changes since it is inert and cannot conduct heat. The heating of the active bead causes an imbalance in the circuit which is interpreted and displayed as a reading (usually % LEL).


The Xintex« Company (www.fireboy-xintex.com/) line of Life's Safe products include everything you need for outfitting a complete and safe gas detection system include:

- Detector & Sensors
- Remote Status Indicator Panels
- Cable Splitter and Connections
- Test Kit


Methane Gas Detection System

The contemporary design Xintex« Methane S2B-M-X-Display-D Monitor / Gas Detector constantly monitors the level of highly explosive methane levels.

The Xintex« Model CMD-4MR-RLY shown in photo (right) is the most advanced CO detector available from Fireboy-Xintex. This inovative detector allowing up to 6 gas detectors to be relayed (linked) in series.Low current draw, 12 VDC operation, CMD-4MR-RLY is expertly designed for Marine use.

LEL sensors

LEL sensors are usually guaranteed to last one or two years, but they can last over four years. There are numerous factors that may decrease the lifespan of an LEL sensor. Dropping the sensor could easily cause the fine wire inside to break. A fuel rich but oxygen deficient environment can lead to sensor failure due to a build up of carbon, tar and unburned fuel on the active bead.

Tetra-ethyl lead (found in leaded gasoline), volatile silicone oils and silicone (RTV) products that off-gas during curing, halogenated hydrocarbons (Freon, methylene chloride etc) and very high concentrations of high hydrogen sulfide or other sulfur containing gases are poisonous to sensors and can cause them to break. When a sensor becomes poisoned, the first gas that it loses sensitivity to is methane. In other words, a sensor may not be able to detect methane, but it can still reliably identify levels of other combustible gases.

This is important to keep in mind when calibrating with pentane or gases other than methane. Some manufacturers are now offering methane-based "equivalent gases" to test sensors for poisoning while still allowing the sensor to be calibrated to a sensitivity scale other than methane.

To calibrate LEL sensors

Most LEL sensors are non-specific and will respond to all combustible gases. The difference is in the amount of heat produced on the active bead in the LEL sensor for various combustible gases.

If the gas you are detecting is different from the gas you used for calibration, your monitor will give % LEL readings on the display based on your calibration gas. Therefore, these readings may be higher or lower than they should be. In the case of pentane, your reading will be lower than the actual levels if the sensor was calibrated with methane. Manufacturers provide LEL correlation factors with their units so you can calculate the LEL of the sampled gas based on your calibration gas.

It is best to calibrate your monitor with the gas that you expect to find whenever possible. If you cannot calibrate to the specific gas, calibrate your instrument with a gas that reacts the closest to it. Also, make sure that you have the alarm set at 10% LEL or less because the differences due to sensor response at this level are minimal.

Problems with their CO detectors going off

Make sure your back up detector has a digital display of PPM. Are you at anchor? it is important to have the bow into the wind with exhaust being carried away from living space. When moving at slower speeds many boats create negative pressure in cockpit area and CO is drawn in.

Easy way to check if it is coming up through the sink drain is to run at idle, shut off the lights in the aft cabin and shine a flashlight beam across the sink. It'll show fumes/exhaust rising. Get a new "back up" meter with a digital readout and see if you are getting CO in the cabin or you have a problem with the wiring etc. Also be aware batteries emit trace hydrogen when being charged and will set off CO detectors.

There are many reasons a CO detector will sound off. Many other have seen brand new boats set them off from all the chemicals used to manufacture a boat called "Outgassing" carpet vinyl resin etc. There are lights on them that will flash a pattern related to a code the manufacturer has the code IDs. Sea Ray mostly uses Xintex units and the have a life expectancy. (http://www.fireboy-xintex.com/)

Charging battery and signs of a battery issue

Actually it's CO not CO2. When batteries are charging they emit Hydrogen which will cause CO detectors to alarm. Most CO detectors have a useful life of 5-7 years before sensors begin to fail.

A fully charged battery will hold 12.6 volts (2.1v per cell) anything beyond that is a surface charge that will fall away quickly with a light load, they usually charge at 13.6 - 14 volts. If you are charging at 16.5 volts rate you may be overcharging the batteries which would explain the low water level.


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