Headquartered in Wrexham, Wales, ESI Technology Ltd designs and manufactures pressure transducers and transmitters, serving a multitude of industries, including aerospace, defence, oil & gas, subsea, medical, automotive, marine, process and general industrial markets. All of the company’s pressure transmitters are manufactured in-house and by hand, ensuring the utmost quality and care goes into the build of every single unit in production.
Incorporated throughout the ESI range, silicon on sapphire (SOS) sensor technology combines silicon and sapphire to create a very durable sensor. Because the silicon is grown onto the surface of the sapphire, it is incredibly stable and exhibits virtually no hysteresis. With its outstanding insulation properties, the sapphire protects the strain gauge from electromagnetic pulse radiation and allows the sensor to operate over a very wide temperature range without loss of performance. It can endure high over-pressures and provides superb corrosion resistance. The excellent elasticity of the sapphire ensures high repeatability, which is a highly desirable characteristic for sensors.
One of the advantages of employing SOS technology is that the titanium pressure diaphragm is welded to a titanium threaded pressure port, so no o-ring seals are required. The method also ensures high accuracy, high resistance to over-pressure and pressure transients, excellent chemical resistance, and stable operation at elevated temperatures. The devices can provide a high sensitivity of 10mV/V to 20mV/V and operate in pressures from -1 to 5000bar with the high pressure HP range machined from a single titanium piece.
Digital pressure measurement
ESI has a growing range of digital pressure measurement solutions suitable for most applications, including industrial, test and high temperature environments.
The GD4200-USB Dynamic Digital pressure transducer offers pressure ranges from vacuum to 5,000bar, a sample rate software selection up to 1,000Hz, accuracy (NLHR) +0.15% of span BFSL, a hydrogen compatible option and support for easy integration with applications created by C#, VB, Labview and Excel VBA (api dll library).
In addition to the pressure measurement performance of the GD4200-USB, what makes this product stand out is the ESI-USB software. Freely downloadable from the company’s website, the software includes features such as easy leak-testing, temperature analysis and auto-updating. Users of the sensor can operate it with the peace of mind that they are always running with the most up-to-date and optimal version of the software.
On-brand, professional test and report certification can also be created with ease. Using the ESI-USB software, users can create and save templates of personally branded test certificates and reports. These can be set up with user-defined parameters, ensuring only the most important data is being presented, with the user’s own company brand.
The HI6000 high temperature pressure transmitter
With a digitally compensated temperature range from -25 to +135°C, the HI6000 offers a range of outputs and pressure ranges, as well as a high accuracy option, and it is ESI’s most flexible high temperature product.
The RS-485 pressure transducer series
Developed due to increased demand from its clients, the RS-485 series offers pressure measurement solutions through digital, high accuracy communication. The range features a general purpose, high pressure and subsea variant. Pressure ranges up to 5000 bar can be handled with a 1200m communication distance, selectable baud rate and resistance to noise interference.
Collectively, ESI’s digital range can cover applications including AUV/ROVs, hydraulic systems monitoring, test and laboratory environments, oil, gas and other process liquids, a wide range of industrial environments, medical and laboratory testing, aerospace, refrigeration, pneumatic, compressor, HVAC and engine monitoring systems.
Oil gas & subsea
Applications for the oil, gas and subsea sectors have become a speciality of ESI. The ability to meet specialist requirements for the subsea market can be illustrated by the evolution of the PR3913 control valve pressure transmitter. This device features operation at 3,000m submersion, the ability to measure up to 1,000bar reliably for up to 20 years, secondary containment to 1,600 bar for environmental protection should the sensor be over-pressured and Environmental Stress Screening (ESS) to ensure long-term stability and extended service life. The transmitter has a compact housing with special process connections and a water-tight electrical interface and can be constructed in corrosion-resistant materials such as Inconel 625 and titanium.
Following on from the success of the PR3913, ESI has also incorporated dual redundancy into the transmitter design. Two independent sensors and electronic circuits are incorporated into the existing housing to create the PR3915. This means substantial cost reduction in materials used in the construction of the valves by making them more compact. Additionally, the PR3920 subsea differential pressure version was developed based on the same principle offering high accuracy differential pressure measurement on chemical injection valves.
The development of the PR3914 subsea pressure transmitter has allowed ESI to fulfil the need for specialist subsea and oil industry applications. With a submersion capability of up to 6,000m depth, the PR3914 is housed in a fully welded body, and wetted parts that conform to the NACE recommendation for material corrosion resistance. With a pressure range of up to 2,000bar, this model is highly suited to ROV and deep sea test equipment, and provides a solution for accurate long-term measurement, with the intention of permanent immersion.
ATEX & high pressure
ESI has an extensive range of intrinsically safe transmitters with ATEX and IECEx approval for explosion protection in:
- Flammable gases (zone 0)
- Dusts (zone 20)
- Mining areas (group I M1)
The most common protection method for process instrumentation is Intrinsic Safety (IS), and it is the protection method used in ESI transmitters. With these instruments, the low-voltage electronics are designed to be incapable of releasing enough energy thermally or electrically to cause an ignition of flammable gases or liquids. To achieve this, there are limitations set on levels of voltage, current, capacitance and inductance such that the available energy at a sparking device is below the minimum ignition energy of the potentially explosive atmosphere.
Hydrogen compatible pressure measurement
One of ESIs most recent ranges of pressure measurement solutions, the H2 range, is compatible with hydrogen-based environments, and is available in general industrial (GS4200H), high pressure (HP1000H) and high accuracy (HI2000H) variants, as well as a digital transducer (GD4200HUSB), available with a combination of ATEX and DNV-GL certification on selected models.
Samples of the materials used in the manufacture of the range were tested based on ISO 11114-2:2017 in accordance with the European Regulations EC 79/2009 and EU 406/2010 to determine an ‘embrittlement index’ of the material when placed in a saturated environment over extended periods. Results have provided a pass rating for the compatibility of the material against hydrogen.
The pressure diaphragm and threaded pressure port are machined from a specialist titanium alloy specifically designed to withstand harsh and demanding environments. This, along with the non-oil-filled sensor and high-integrity stainless steel housing, results in a robust and versatile unit that offers excellent media compatibility across a range of environments.
The hydrogen range also benefits from the same silicon on sapphire (SOS) sensor technology used throughout the ESI product range, providing outstanding performance, stability and highly accurate pressure measurement.
The GS4200H Industrial pressure transmitter series offers pressure ranges to 1,500 bar, excellent corrosion resistance, high stability performance at low cost and high resistance to overpressure.
The HP1000H high pressure transmitter series offers pressure ranges to 5,000 bar, is machined using a single piece of special high strength Titanium alloy and has a high resistance to overpressure and pressure transients.
The HI2000H Hispec pressure transducer series offers pressure ranges to 1,500 bar, delivers high accuracy and performance with a specialist titanium alloy sensor for excellent chemical compatibility and is available in a TEDS Version.
The GD4200HUSB Dynamic Digital pressure transducer series offers pressure ranges from vacuum to 5,000 bar, up to 16 pressure output readings, accuracy (NLHR) +0.15% of span BFSL and ESI-USB Software providing customised test reports and certificates.
Applications for ESIs H2 range include hydrogen production and storage, engines, marine propulsion and re-fuelling, and a range of industrial and laboratory environments