February 21st, 2012
Impress Sensors also offer a full range of pressure transmitters, screw-in transmitters, submersible probes and level control switches, all with SIL2 (Safety Integrity Level 2) approval for hazardous environments.
The product range is is targeted at safety and hazardous area applications, including process manufacturers, chemicals, oil and gas, nuclear and Atomic Weapons establishments. The devices are also suitable for medical device applications.
The process industry demands the highest degree of safety and reliability these days. The current Safety Integrity Level (SIL) international safety standard provides suppliers and users with a common framework on which to design products and systems for safety related applications. The standard also provides a more scientific, numerical approach to specifying and designing safety systems, enabling the nature of the risk to be quantified.
SIL means risk reduction to a tolerable level. The required safety level of a process plant is classified in accordance with the international IEC 61 511 standard and depends on the risk constituted by a plant. The IEC 61 508 standard describes the requirements of electrical, electronic and programmable electronic devices used in such plants. Both standards subdivide plants and devices into 4 safety levels, from SIL1 for low risks, to SIL4 for very high risks. The allocation to these safety levels is based on the use of a risk graph and depends on:
• Extent of possible damage
• Frequency of persons present in hazardous areas
• Possibility of damage prevention
• Probability of an unwanted event occurring
The standards also describe the type of risk assessment and procedures for integrating certain safety functions into sensors and plants. Generally, the significant hazards for equipment and any associated control system have to be identified by the specifiers or developers via a hazard analysis. The analysis identifies whether functional safety is necessary to ensure adequate protection against each significant hazard.
Examples within safety related systems for mechanical engineering include auxiliary disconnected systems; fire detector and gas warning systems; monitoring of turbines; safety interlock and auxiliary disconnected systems for machines; devices for medical applications; and remote monitoring based on network, handling and programming of procedural constructions.
For more information on Impress Sensors’ range of SIL2-certified pressure, temperature and level control switches, contact the sales department at Impress Sensors & Systems Ltd on 0118 981 7980 or visit the website at http://www.impress-sensors.co.uk/sil-products.htm
February 4th, 2012
OEM pressure transmitter is ideal for refrigeration and cooling systems
A new stainless steel welded pressure transmitter for refrigeration, chillers and air conditioning systems is now available from instrumentation specialist Impress Sensors & Systems Ltd.
The new 17.609 G welded pressure transmitter has a stainless steel housing, pressure port and diaphragm and requires no O-ring seals. The transmitters can operate in temperatures from -40 deg C to + 125 deg C, making them ideal for OEM pump and compressor applications within refrigeration, chillers, air conditioning and other process cooling systems.
- 17.609G OEM pressure transmitter,
Sam Drury, Sales & Marketing Director at Impress Sensors & Systems comments: “Refrigeration plants use gas, liquid and mechanical energy to move heat from one place to another. Compressors and pumps are required to repressurise the gas, and discharge the liquid through cold water heat exchangers or cooling fans.”
“The refrigeration media, normally R134a in Europe, is mixed with an oil or lubricant, of which there are many different types. This is to ensure that the refrigerant can be transported easily through the pipework. However, when it comes to selecting a pressure transmitter for the pumps or compressors within these systems, it is very difficult to achieve compatibility between the refrigeration media [oil or lubricant] and the O-ring seals on the pressure transmitter. The 17.609 G is ideal for these types of applications, as it operates oil-free and is welded so it requires no O-rings.”
The pressure transmitter is available in compound nominal pressure ranges from 0… 6 bar up to 0… 60 bar and from –1… 6 bar up to –1… 60 bar. This means the sensors can measure pressures in a vacuum, as well as being resistant to vacuum conditions. The sensors also offer up to three times overpressure or higher.
The pressure transmitters are designed to withstand the vibration and shock levels normally associated with pump and compressor applications. The sensors are also supplied with a ¼-inch flare connection, the industry standard for refrigeration applications.
Standard output is 2-wire, 4…20mA, with optional 3-wire, 0…10V or 3-wire ratiometric also available.
For more information on the new 17.609 G pressure transmitter, please visit the website at www.impress-sensors.co.uk or call the sales team on 0118 981 7980.
February 3rd, 2012
New oil-free stainless steel pressure transmitter is ideal for oxygen and mobile hydraulics applications
Instrumentation specialist Impress Sensors & Systems Ltd has launched a new oil-free stainless steel welded pressure sensor for oxygen applications, where silicon oils or elastomeric seals cannot be used. The sensors offer high overpressures (typically three times the nominal pressure rating) and so are also suitable for mobile hydraulics and machine engineering, where pressure spikes or peaks are present.
The new DMP335 has no O-ring seals, which means the sensor is easier to keep clean and sanitise for medical applications. The sensors are completely de-greased before despatch to the customer.
DMP335 Oil-free oygen all stainless steel pressure transmitter
Sam Drury, Sales & Marketing Director at Impress Sensors & Systems comments: “Oxygen is present in many process manufacturing environments, medical applications, as well as filling and bottling plants. The oxygen needs to be transported safely through these processes without coming into contact with oil or other contaminated fluids, which could cause an explosion. The all-stainless steel, oil-free design of the DMP335 pressure sensor makes it ideal for these types of environments.”
The sensors are ATEX-certified (intrinsically-safe) for hazardous gas and dust environments (Zone 0 and Zone 20). Nominal pressures are available from 0… 6 bar up to 0… 600 bar. Permissible temperatures are from –40 deg C to +125 deg C. Output signal is either 2-wire: 4 to 20mA, or 3-wire: 0 to 10V.
A version of the sensor is also available with 4-digit LED display and 1, 2 or 4 PNP contacts. The digital display is configurable and can be rotated through 180 degrees.
For more information on the new DMP335 pressure sensor, please visit the website at www.impress-sensors.co.uk or call the sales team on 0118 981 7980.
January 14th, 2012
Marine-Approved Level and Pressure Sensors now available from Impress
Instrumentation specialist Impress Sensors & Systems Ltd has launched two new marine-approved sensors for level and pressure measurement of storage and ballast tanks. Both sensors are approved by DNV and Germanischer Lloyd.
The new LMK 458 is a hydrostatic probe with ceramic (Al2O3) diaphragm that is suitable for level measurement in marine storage/ballast tanks and draught monitoring, as well as applications in the water industry such as desalinization plants and drinking water filtration.
The probe uses a capacitive ceramic sensor element that provides a high resistance to overpressures. The transmitter is protected to IP68 and provides good resistance to chemicals and high long-term stability.
Marine Approved Pressure Transmitters
An optional intrinsically safe (IS) version of the LMK 458 is also available. This version is ideal for measuring the pressure of various fluids in harsh marine environments, including Zone 0 ATEX areas. Other options include different housing materials, either stainless steel as standard or a Cupro-Nickel (CuNiFe) sea water-resistant version. Other options include screw-in or flange-mounted versions, as well as other accessories such as probe flanges and mounting clamps.
The LMK 458 has a diameter of just 39.5mm and is able to operate in temperatures from -25 deg C to +125 deg C. The sensor is accurate to 0.25% FSO (to IEC 60770). Nominal pressure ranges are from 0-40 cmH2O, up to 0-200 mH20.
In addition to the LMK 458, Impress Sensors has also launched a marine-approved pressure transmitter. The DMK 458 is a pressure transmitter with ceramic diaphragm that is suitable for monitoring pressures in a variety of marine and offshore applications, including loading and unloading systems, level measurement in ballast and storage tanks, draught monitoring, and anti-heeling systems used on ferries and cargo ships, which prevent heeling of the ship during loading and unloading.
The DMK 458 offers high overload pressures, excellent accuracy and high temperature resistance. The transmitter is available in nominal pressure ranges from 0-40mbar up to 0-20bar. As well as threaded versions, the transmitter is also available in various flush mounted versions, which are ideal for measuring pressures of viscous, pasty and polluted media.
The DMK 458 can operate in temperatures from -40 deg C up to +125 deg C. The sensor is accurate to 0.25% FSO to IEC 60770. An optional IS-version for Zone 0 applications is also available.
For more information on the LMK 458 or DMK 458 pressure transmitters, please visit the website at www.impress-sensors.co.uk or call the sales team on 0118 981 7980.
January 13th, 2012
New rugged transmitters offer pressures up to 6,000 bar
Instrumentation specialist Impress Sensors & Systems Ltd has launched a new range of stainless steel pressure transmitters that are suitable for a wide range of high pressure applications, including hydraulic circuits, water jet spraying and other high pressure chemicals, pharmaceuticals, oil, gas and petrochemicals applications.
The design of the new DMP304 ultra-high pressure transmitter is based on a compensated strain gauge, bonded onto a stainless steel diaphragm. With its rugged, stainless steel housing, the sensor offers a maximum nominal pressure of 6,000 bar, making it suitable for use in a variety of harsh, high-pressure industrial applications.
DMP 304 Ultra High pressure transmitter
Sam Drury, Sales & Marketing Director at Impress Sensors & Systems Ltd comments: “The DMP 304 is ideal for applications where the customer is looking for a robust, high precision, high reliability pressure transmitter that also offers very high nominal pressures. A version of the sensor is also available for intrinsically-safe, hazardous gas and dust applications.”
Special characteristics of the sensor include the ability for the user to adjust the offset and span (difference between FSO and zero) via front-sided potentiometers. This means engineers can take out sensor drift or any residual pressures in the system and can also scale the output to their preferred pressure range.
The DMP 304 is accurate to 0.5% FSO according to IEC 60770. An optional 0.25% FSO version is also available. For users wishing to calibrate the transmitter after installation, an MIL/Bendix connector plug option is supplied as standard, enabling shunt calibrations to be carried out, simulating up to 80% of FSO.
The DMP 304 is available in nominal pressure ranges from 0…2,500 bar up to 0…6,000 bar. Output signal is 2-wire, 4 to 20mA or a 3-wire 0 to 10V version is available on request. The response time of the sensor is less than 2.5 milliseconds.
For more information on the DMP 304 range of ultra-high pressure transmitters, please visit the website at www.impress-sensors.co.uk or call the sales team on 0118 981 7980.
February 23rd, 2011
The introduction of various digital electronics and the continuous development of sensor technology have resulted in the overlapping of sensor specifications. To some extent, this overlap is a result of manufacturers marketing just one technology. In the last few years the capability of pressure transmitters has been maximised to such an extent that you can now find pressure transmitters for all kinds of applications. Here we have discussed two extreme conditions which have been effectively streamlined by the use of pressure transmission technology.
Pressure transmission in hydraulics
Pressure transmitters in this application are exposed to water thrashing and cavitations. This mainly happens when these devices are placed in a water line and the flow of water is stopped. Pressure transmitters are also exposed to these conditions if they are mounted right after valves. For this reason, it is important to use transmitters that are robust and which have integral pulse snubbers.
Heavy-duty machinery for construction
These machines have pressure transmitters attached to hydraulic systems and engines. It is important for transmitters used in rough-terrain equipment to be capable of functioning under tough environmental and mechanical equipment. They are usually exposed to high levels of vibration, shock, moisture and dust. Due to this, the sealing and connectors of the pressure transmitters should be good.
Besides these, pressure transmitters used in refrigeration systems and power plants are also exposed to harsh conditions. For this purpose, it is important to check the application for pressure transmitters and according to those requirements, use devices which can withstand these specific conditions.
February 22nd, 2011
Pressure transmitters are predominantly used in industries which measure the level or flow of liquids. However, other industries have also begun using pressure transmitters to measure and maintain pressure. These are used on machinery that exerts pressure. Pressure transmitters are very common in safety equipment.
If machinery or equipment releases more pressure than required, then the pressure transmitter sounds an alarm. These transmitters are cost-efficient, flexible to use and very user-friendly. The benefits that pressure transmitters offer make it very popular in industry and on utility plants.
The uses of pressure transmitters
Factories use pressure transmitters to monitor pressure levels in various manufacturing processes. Each process requires a fixed rate of pressure to be maintained. Using too much or too little pressure can be fateful. Pressure transmitters help in aiding and maintaining the exact levels of pressure. Pressure transmitters also help prevent machinery from overheating due to a constant increase in pressure output. Besides this, pressure transmitters are also used to maintain liquid pressure in vehicles and other applications.
Pressure transmitters are also commonly used in the following equipment to maintain pressure levels:-
• Construction equipment that use hydraulic systems
• Engines in ships, steamers and power plants
• Water booster pumps
• Vehicle engines
• Refrigerator systems
The types of pressure transmitters
There are two types of pressure transmitters. One is the gauge or absolute pressure transmitter and the other is a differential pressure transmitter. A gauge pressure transmitter measures the pressure of a single process or a set range. A differential pressure transmitter measures pressure on a large range and on multiple processes.
February 15th, 2011
Pressure transmitters are an integral part of manufacturing facilities across the world.
Given below are the different ways that a pressure transmitter can be used in different industrial settings:
Monitor the applied pressure
This is the first use of a pressure transmitter. They are used in industry to monitor the pressure within an industrial setting. Pressure is applied in an industrial system to accomplish a desired outcome. However, sometimes excessive application of pressure affects the process. Similarly, application of too little pressure can affect the machine. Pressure transmitters thus allow real-time measurements of the industrial environment.
Pressure levels pass beyond acceptable limits
In certain manufacturing applications, pressure transmitters are used to ascertain that there is no pressure build-up above acceptable limits. Therefore, pressure transmitters make sure that the pressure remains within the acceptable levels. In case the pressure crosses acceptable levels, the transmitter will immediately alert the machine operator. The operator then has to shut down the process or the process shuts down automatically.
Measure liquid pressure in industrial applications
Pressure transmitters can also measure liquid pressure in industrial applications. They can thus allow the operators to take optimum care of expensive industrial equipment. Transmitters can also monitor the overall level of oil pressure in an engine for example.
Pressure transmitters thus play an important role in facilitating the smooth flow of industrial systems and processes.
February 9th, 2011
Pressure transmitter is a commonly used term in several manufacturing plants. More than a term, it is a device that is used in different manufacturing plants. This device can be described as a transducer which is connected with amplification current. This permits the electric signal to pass through long distances.
However, pressure transmitter life can often pose a problem. Mentioned below are some tips which can enhance the shelf life of the device. Such tips will also help in the maintenance aspect immensely.
Tips and suggestions
Firstly, workers should remember that pressure transmitters are supposed to be placed at the ground level. They can also be placed near the walk way level. This will help the users and provide them with better access for installation as well as maintenance. Mounting the pressure transmitters at the ground level will ensure that the users can access it quite easily for pressure calibration.
Keep in mind that these devices should not be mounted in locations which are subjected to vibrations. You should also ensure that the thermal operating points do not exceed the prescribed limit. A longer shelf-life can also be guaranteed by operating the device within the prescribed temperature limit.
You can provide efficient thermal transfer by the use of an impulsive pipe work. This can prove useful in maintaining the operating temperature levels. However, the pipe work should not be blocked.
The above mentioned guidelines can prove useful in enhancing the performance and shelf-life of the device.
February 5th, 2011
Pressure transmitters and sensors are used for the measurement of liquid and gas pressure. Pressure is the physical property which helps retain the original form and structure of the liquid or gas. It is measured in units of force per unit of area. The pressure sensor measures pressure and converts it into an electrical signal. This signal is usually in the form of digital LED readings.
Application of pressure sensors
Pressure sensing technology is used for the optimisation of all kinds of results. These results may be the output of an industrial process or any other mechanical process. One of the most important functions of pressure transmitters is to maintain the required levels of safety.
In industrial manufacturing processes, pressure sensors regulate the amount of pressure that gets applied. Thus, pressure sensing technology ensures that we achieve the desired results. There are several different instances when different quantities of pressure are exerted and sensors help us to keep a vigilant eye on these pressure quantities in real time.
Pressure sensors maintain required pressure and raise an alarm in case the pressure exceeds beyond danger levels so that the industrial process can be stopped in the right time. Thus, pressure sensing technology helps maintain high levels of safety and saves costs and other damages.
One of the most commonly found pressure sensors is the one in our motorcycle oil gauges. Oil pressure needs to be maintained at one constant level for the vehicle to be running smoothly. This type of pressure sensor is a diaphragm-spring type. The resistor adjusts the voltage levels to achieve the perfect balance between oil pressure and the voltage level. The imperfection in the balance is displayed by the indicator light to let you know that the oil pressure is low.