Month: September 2022

How often should fire alarms be tested?

Posted on by Scott Hackett

The Regulatory Reform (or Fire Safety) Order 2005 states that where it is necessary (whether it’s because of the features of the building, the activity that is completed there, any present hazards, or any other relevant circumstances) it is legally required that a responsible person must make sure the premises are, to the suitable extent, equipped with working fire detectors and alarms, to ensure the safety of all relevant individuals on the premises.

Subsection three of the order says that the chosen person to implement and maintain these measures must be competent. However, a responsible person (or someone appointed by the responsible individual) can conduct testing of the fire alarm system after being trained to do so properly.

What are the different types of fire alarm systems?

There are two main types of fire alarms for commercial buildings, manual and automatic.

The manual fire alarm system needs someone to activate the alarm by a manual call point (outstation), which will register on the panel of the fire alarm. Outstations need to be situated on escape routes and fire exits, with extra outstations in areas at greater risk like commercial kitchens, laundries, and plant rooms.

An automatic fire alarm system is automatically activated by either detecting heat or a certain amount of smoke. It will also have the ability for a user to manually start the alarm near an outstation, which will register on the master station.

Fire alarm systems within commercial or business premises can come in two variants, conventional or addressable. A conventional system will see a detected fire (whether via an automatic detection system or manual activation at a call point) registered on the fire alarm control panel in one of the highlighted zones, for example, the ground floor, warehouse, or plant room, depending on how the system was designed and installed.

An addressable fire alarm system, where a fire is detected and registered on the control panel as a specific location or address within a zone. For example, through an automatic smoke detector in a boiler room on the ground floor, or a manual call point by the rear fire exit.

The type of fire alarm system you need for your premises should be determined and recorded in a current fire risk assessment. Also, to help reduce the risk of a fire in your premises, you should ensure you have fire resistant cable.

How often should a fire alarm be tested?

In section 25.2 of the relevant British Standard regarding testing fire alarm systems confirms that all fire alarm systems in commercial buildings are required to be tested weekly. This is to ensure that there hasn’t been any significant failure and the system is fully in working order.

To test the system, firstly you should create a list of all outstations within the premises as each one will need to be tested in a rotational order, making sure all locations are regularly tested. In smaller buildings, it’s acceptable to test only one location each week.

For instance, in a premises where there aren’t many outstations, they could all be tested over a period of two months in rotational order. In bigger commercial businesses, it might be more suitable to test two or three outstations each week, to guarantee all devices are tested over the same length of time. In the event of a fire in your building, fire proof cable can help buy you more time to ensure everyone gets out safely and there is less damage and downtime to your operations.

Do I need to be trained to test fire alarms?

Section 25.1 says that testing a fire alarm doesn’t need any specialist knowledge and can normally be conducted fairly easily. However, it might be preferable for a competent person to offer initial instruction in testing the system in order for this to be diligently carried out in the future.

The British Standard also states that fire alarm testing can usually be carried out by the occupier of the building. This could be the responsible person, or someone assigned by the responsible person, like a property manager. However, both will need basic instructions in how to do correctly do so.

Summary

Generally speaking, fire alarm systems should be tested on a weekly basis in commercial properties. As well as regularly testing your fire alarm, there are many things you can do to make sure your premises is as safe from fire as possible, including having fire retardant cable.

At TRM, we provide engineered solutions and products that help many industries with their temperature measurement, trace heating, and fireproof wiring with high quality fire cable. Contact us today to see how we can help your business operations.

How beneficial are thermocouple sensors in the automotive industry?

Posted on by Scott Hackett

The automotive industry can benefit significantly from a wide range of temperature measurement solutions including a thermocouple sensor, infrared camera, pyrometers, and temperature controllers. This broad range of products can all provide the best solution for all type of automotive needs. In this article, we’ll explore how useful a thermocouple and temperature related solutions are within the automotive industry, so you can gain a better understanding of how they could help you if your operations are in this sector.

Thermocouples and general automotive testing

In the automotive testing process, measuring the temperature of various components is key. When it comes to measuring thermocouples in brakes, a thermocouple wire bundle can quickly get to a stage where the diameter starts to affect the structural integrity.

To effectively deal with this issue, you could get an extra thin and highly accurate type K thermocouple cable. Our thermocouple wires at TRM allow high performance temperature measurements that are consistent and reliable. These thermocouples are designed to handle rigorous conditions, which makes them ideal for use in automotives.

Brake block and disc temperature measurement

A major application for temperature measurement technology in the automotive industry includes measuring the temperature of brake system elements. The surface temperature of the disc has a direct impact on braking performance, which is why temperature measurement systems are essential in the manufacture of efficient braking systems as well as for regular monitoring in the finished product.

The measuring system needs to be able to record the wide range of temperatures that can be found on a brake disc and pad. This is typically done by fitting thermocouples to the disc and pad, and using collector rings in the circuit. Optical measurement systems like thermal cameras and scanners, are also used during brake tests. Thermocouple systems are useful in determining surface pressure distribution within brake pads too.

Exhaust gas temperature measuring

A high-quality thermocouple probe with wide temperature ranges and low response times are very beneficial for applications where surface contact is required, such as for monitoring automotive exhaust temperature. Probes can come in all the common thermocouple types for various applications (K, T, and J).

Turbo chargers are an important part of modern engines, with high rotational speeds and their versatility in coming in different shapes and sizes, a turbo charger is a complex subsystem in itself. Shielding the turbo from excessive temperatures is vital as it is regularly exposed to the high temperature exhaust stream.

This means a reliable thermocouple sensor with a fast response will play an essential role in the control loop. An example of this is a mineral insulated thermocouple cable. It’s thin, strong, and durable enough to last the full lifetime of the car, without compromising on mechanical strength.

Simulated exhaust temperature measurement

Manufacturers are required to test all components to their limits during automotive testing to see how they perform in conditions they are likely to encounter during the service life of the vehicle. Many polymer components that are found in modern automobiles have gone through heat stress tests if they are within close proximity to a heat source.

For example, the bumper is positioned close to the engine exhaust gas, where temperatures can get very high. This means the bumper material needs to be tested to make sure that it’s not negatively affected by the higher temperature of the exhaust, leading to thermal degradation of the polymer, or potentially even a fire, in the worst case.

In this modern testing process, the exhaust system is exposed to simulated heat from a custom electrical heater. A number of thermocouples are recommended for this to measure the temperature at different heat-vulnerable stress points.

Usually, complete accuracy is not important to this application, so thermocouple wires are chosen to ensure the application is cost-effective. This will be helpful in saving money as these heat tests often involve monitoring a large quantity of thermocouples in the entire route of the exhaust system.

 

Contact TRM today for an expertly engineered solution to all your temperature measuring and thermocouple needs within the automotive industry.

Benefits of MI Cable

Posted on by Scott Hackett

What is mineral insulated cable?

Mineral insulated cable (MI) is a specialist type of cable that is designed to be used in high temperatures and severe environmental conditions because it’s not flammable, so it won’t be damaged by heat.

MI cable is generally made up of copper conductor wires inside a sheath that can be made of copper, stainless steel, or Inconel, (other materials are available on request). It is insulated by packed minerals specifically magnesium oxide (MgO). Magnesium oxide is the perfect electrical insulation material because it is resistant to oxidation, ionizing radiation, and it’s stable at high temperatures both, physically and chemically.

When the MI cable has been packed with MgO, the mineral insulated cable is annealed and drawdown in size to reach the required diameter. The outer sheath works to protect the conductors, for example thermocouple wires inside from heat, chemicals, or other damage from the environment. For fire proof wiring cables the copper sheath can be covered with an extra, coloured low smoke and fume (LSF) sheath to add in both identification and an additional layer of protection from corrosion.

An MI cable can have a number of wires depending on the application, the configurations that are used most often in temperature measurement are 1, 2, or 3 pairs of conductors. Specifically designed mineral insulated cables might include extra thermocouples in customised configurations. MI cable can come in a range of diameters and lengths, depending on the unique requirements for their use. All TRM MI cables are extensively tested before shipping on to our clients.

What is MI cable used for?

Mineral insulated fire survival cables where created with critical and essential circuit protection in mind. They are ideal for use in protecting buildings and structures for example, high-rises, tunnels, airports, healthcare facilities, and industrial or petrochemical plants.

Additionally, temperature sensors made from MI cable like RTDs and thermocouples, are commonly used in corrosive and high temperature environments such as heat treatment, solid waste incinerators, sintering powdered metals, firing ceramic metals, fuel fired heat exchangers, and nuclear or hydrocarbon-based energy plants.

What are the benefits of MI cable?

Corrosion and oxidisation resistant

The metal sheath that covers MI cable works to protect the conductor wires from oxidising when used in chemically active or damp environments. A high level of corrosion resistance means mineral insulated cable is great for use in areas where failure and replacement could be extremely dangerous or even impossible to do.

For instance, MI cable is used in nuclear plants to monitor core temperatures. It would be incredibly dangerous if the temperature controllers were not getting accurate readings, and it would be challenging to attempt to repair or replace the cables in this type of environment.

Non-reactive insulation

The MgO within MI cables offers unparalleled non-reactive insulation, which prevents the conductor wires from coming into contact with either each other or caustic substances like oils, solvents, or water. This is to make sure for example that the thermocouple probes always stay accurate, which is vital in applications like heat treating or sintering where the quality of the product could be negatively affected by fluctuations in temperature.

The insulation doesn’t burn

The insulation inside MI cables does not burn, meaning it is ideal for fire protection applications where it could be disastrous if a fire broke out. MI cables are ideal for critical applications such as medical devices, power plants, and oil rigs. Simply put any essential circuits would be safer with the installation of mineral insulated cables.

High levels of precise accuracy

Since the metal sheath and MgO insulation also protects thermocouple and RTD probes, they’re not easily subject to malfunction or inaccurate temperature measurements. MI cables are carefully calibrated to achieve international standards, meaning they provide accurate and precise temperature measurements across long duty cycles with very little to no loss of accuracy at all.

Also, thanks to the mineral insulation, MI cables can effectively function in high temperature conditions without their accuracy levels being affected. This makes them very useful for kilns, firing ceramics or heat-treating metals, or any other high temperature process.

These cables retain their accuracy during and after exposure to high temperatures, making them ideal as a temperature probe in these kinds of operations. Additionally, for industries like medical devices or aerospace where safety standards are enforced strictly and deviations from processes could lead to serious or even life-threatening quality issues.

Contact TRM today for find out how we can help you with our fireproof wiring, temperature measurement, and trace heating expertise. We can create tailored solutions for business in many industries to ensure the safety of their processes.

What is a thermocouple and where is it used?

Posted on by Scott Hackett

What is a thermocouple?

A thermocouple is a sensor that is used for measuring temperature. The sensor has two dissimilar metal wires joined at one end and is connected to a thermometer or another thermocouple-capable device at the other end. When they are correctly configured, they can provide temperature measurements across a broad range of temperatures.

Stable thermocouples are highly versatile as temperature sensors, and so are often used in various applications, from industrial use to a regular thermocouple you can find on utilities and standard appliances. There are many different models and technical specifications for thermocouples, so it’s very important to understand the basics of how it works, its structure, and its ranges to get a better insight into what type of thermocouple and material are right for your application.

How does a thermocouple work?

When two wires made of different metals are joined together at both ends and one of the ends is then heated, there is a consistent current which flows in the thermoelectric circuit. If the circuit breaks at the centre, the net open circuit voltage is a part of the junction temperature and composition of the two metals. This means that when heat or cold is applied to the junction of the metals a voltage is produced that can be linked back to the temperature.

Thermocouple types

Thermocouples can come in multiple different calibrations or combinations of metals. The most commonly used are the base metals referred to as N, T, E, J, and K types. As well as this there are high temperature calibrations called noble metals. These are types R, S, C, and GB.

Where are thermocouples used?

Thermocouples are the most commonly used temperature sensors in the world because they can measure a wide range of temperatures, are durable, and are relatively inexpensive. When it comes to high temperatures, fast response, small temperatures, and a high vibration, you will likely find a thermocouple wire collecting the temperature measurements. Below we’ll be looking at just a few examples of where these sensors are used, so you will know how they can be applied in your operations.

Food applications

Thermocouples are used in many different types of applications within the food and drink industry, such as:

  • Clean-in-place sensors
  • Penetration probes
  • Oven control
  • Food chain monitoring
  • Hotplate control and monitoring
  • Steam kettle temperature control

Extruders

Extruders need high temperatures and pressures. Also, they have a unique thread adapter that works to position the tip of the sensor in the molten plastic under the high-pressure conditions located there.

Measuring low temperature

Type E, K, T, and N thermocouples can all be used to record low temperatures, as low as -200C. However, the alloys used need to be specially chosen for use at these temperatures to meet the published accuracies.

Many manufacturers ensure their alloys are calibrated for use from 0C and above. The same alloys can be used to measure down to -200C, but the accuracy might change slightly from the established values. If you purchase individual calibrations, you can determine offset values.

Furnaces

The right thermocouple for this application will depend on the furnace conditions it will be exposed to. When deciding on the right thermocouple, some factors that will need to be considered are:

  • The temperature capabilities of the thermocouple cables
  • Temperature capabilities of the sheath or protective coating (metal or ceramic)
  • The environment it will be used in (air, reducing, oxidising)
  • The configuration for mounting

Molten metal

It is difficult to measure the temperature of molten metal due to the high temperatures and harsh conditions involved. The only option for getting contact measurements in this area is to use Type K or N Base Metal thermocouples, or Types R, S, and B Platinum thermocouples.

When base metal thermocouples are used, the wires are generally large in diameter, with ceramic insulators and ceramic and/or metal protection tubes. The increased diameter of the Type K or N wires degrade slower to enable enough time for measurements to be taken before the high temperature conditions break down the wires.

Platinum thermocouple wires, unlike the base metal Type K and N, will become soft instead of becoming corroded, due to long term annealing and ultimately fail because of grain growth.

Contact TRM today for help with temperature measurement solutions for your business’ operations.

Everything to know about trace heating

Posted on by Scott Hackett

What is trace heating? 

Trace heating is when the temperature of pipes and vessels is maintained or increased via specifically engineered cables. Trace heating products exist in response to the winter season when temperatures become very cold and can drop below freezing levels. 

When this happens, businesses often look to trace heating as a solution to prevent their vessels and pipes from freezing during the coldest temperatures. This is when pipes can freeze over which might result in them bursting from the expanding ice applying too much pressure. So, the aim of a trace heating system is to stop frost from forming in water pipes by keeping temperatures at a certain level. 

Also, heat tracing can be applied in processes that need temperature maintenance like insulating steam pipes. Another example is where certain liquids need to be kept at a specific temperature so they can be safely transported. In these cases, heat tracing can still be applied even without cold temperatures. 

How does trace heating work? 

Trace heating is done by connecting specifically engineered cables made from a resistance element to the vessel or pipe. The electric cables then have the job of process temperature maintenance by swapping heat loss with their power output. Ohm’s law dictates that connecting a voltage with a wire or cable will lead to a supply of power, which is then changed into heat energy by the heat tracing system. 

Trace heating cables have two copper conductor wires that are the same length, which forms a heating zone with a resistance filament in position. With a supply of fixed voltage, a consistent wattage is generated which in turn heats up the zone. A thermostat monitors the trace heating cables to make sure that the correct amount of thermal energy is produced so the cable won’t underheat or overheat. 

What are the different types of trace heating UK? 

Series resistance trace heating 

A series resistance heating cable is made up of a high-resistance wire that is usually insulated and enclosed within a protective cover. Thermal energy is created from the resistance of the wire when it is powered at s specific voltage level. The main benefit of a series resistance heating cable is that it often costs less than other options and is capable of maintaining very high temperatures for longer lines. 

Therefore, series resistance trace heating cables are normally made to be a fixed length and can’t be shortened in the field. This is because any break or failure at any point along the line would lead the full cable to fail. So, series resistance trace heating cables are often used for longer pipeline heating procedures. 

However, the circuit still needs to be monitored and controlled as the resistance material could melt because of overheating. Series resistance trace heating is normally put in place when long pipeline process heating is required, for example on the quay side of load pipes on oil refineries and along oil pipelines. 

Constant wattage trace heating 

The design for constant wattage trace heating cables includes a heating element that is wrapped around two insulated, parallel wires. There are several points throughout the trace heating cable that experiences constant wattage. 

A notch is made in the insulation on opposite sides of the conductors. Then a small heating circuit is created by fusing the heating component to the exposed conductor wire and this is continued throughout the entirety of the cable. Next the parallel wires are separated from the grounding braid by an inner jacket. 

A key advantage of constant wattage trace heating, compared to series resistance heating, is that the former can still work even in the event of an issue somewhere on the cable. In addition, the length of the cable can be altered on site thanks to its parallel functionality, this cannot be done with series resistance trace heating. It’s for this reason that a lot of businesses and industries ask heat trace specialists to install constant wattage trace heating, because of the flexibility you get with it. 

Constant wattage trace heating cables always come with a thermostat when installed in order to monitor and regulate the power output of the cable. This is done to stop overheating and burning out, should the cable ever come into contact with itself. 

Self-regulating trace heating 

Self-regulating trace heating cables that can change depending on the temperature. On a basic level, when temperatures drop below a certain limit, the cable resistance will go down as well. However, the resistance of the cable will increase when the temperature goes above the specified level. 

Self-regulating trace heating cables are made from two equal wires encased in a semi-conductive polymer. The polymer is typically made with carbon which stops the current from overflowing at increased temperatures. The carbon inside the polymer can expand or contract to generate different levels of resistance and heat energy output. 

The length of the cables can be altered in the field. Also, the self-limiting capability of the cable enables it to be more energy efficient as it can lower its output at higher temperatures. Thanks to its feature of conserving energy when the temperature goes up, self-regulating cables can help businesses to save money as less power is used. 

Additionally, these cables have better levels of safety which is particularly desirable in hazardous locations. This is because the power output of the cables won’t go above a certain level as output decreases when the temperature increases. So, it’s not possible for the cables to overheat, which could have been dangerous, especially in areas with flammable gases and vapours. 

How can trace heating be applied? 

Freeze protection 

As previously mentioned, trace heating is often used to protect pipes and vessels from freezing by keeping the temperature at a set level above freezing point. This is done by providing heat energy to balance the level of heat lost through conduction. Keep in mind thermal insulation can only slow down the heat loss process, it can’t prevent it from happening completely. So, trace heating is a good solution to heat loss and frost protection. 

Gutter and de-icing roof 

Trace heating cables can be fitted to the roofs and in gutters to avoid the accumulation of ice or snow. Also, the cables function as a draining path for water from the melted ice to move through to stop overflowing in the rooftops and gutters. 

Overflowing can have a negative effect on the structural integrity of buildings as it can lead to water soaking into cracks or joints. Additionally, the extra weight from the gathering of snow or melted ice can cause indentations and depressions on the rooftops and gutters. So, trace heating is key to preventing unwanted water build-up. 

Anti-cavitation 

Trace heating helps to lower the chance of cavitation occurring in pipes as heating a liquid makes it thinner and reduces its viscosity. The term cavitation refers to the development of vapour bubbles in a liquid caused by fast changes in pressure.  

Shockwaves are created when the vapour bubbles or cavities in the liquid collapse or implode, which degrades the inside of the pipe over time. Also, cavitation can break up the flow of liquid within the pipes. So, putting heat tracing cables in place will lower the likelihood of cavitation as it helps to reduce the pressure difference in the liquid. 

Conclusion 

Thermal insulation doesn’t completely reduce heat loss, so heat tracing is needed for businesses to keep temperatures over a designated level. This is particularly important during the winter season when temperatures can go below freezing levels and frost heaving is likely to happen. 

As professional trace heating suppliers, TRM can help you with your trace heating needs. Contact our team today to discuss your requirements. 

 

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