Due to the worldwide rising energy costs, the energy-efficient operation of refrigeration systems becomes a ‘must’ for all installers, integrators and contractors working in this field. According to estimates from third-party sources, more than 90% of the refrigeration systems worldwide are still not yet equipped with continuous control technologies.

Most of these systems have been optimised and pre-set for certain operating states and refrigeration capacity – which means that they operate outside the ‘optimum’ in all other operating states, whenever less capacity is required. This will often result in a waste of valuable energy. At a point soon, systems without any closed-loop control will no longer be acceptable within the industry.

Therefore, manufacturers and integrators of refrigeration systems are increasingly looking to utilise electronic pressure sensors to control pressure and thus the resulting temperature of the refrigerant with high precision. Our R-1 pressure sensor has been developed specifically for this use and in practice achieves substantial savings in electricity costs for the operators.

 

R-1 Pressure Transmitter for Refrigerants Refrigeration Pressure Sensors

The model R-1 pressure sensors has been specifically designed, developed and optimised for the industry requirements of refrigeration and air-conditioning applications. Its unique construction removes the need to use any seals on the process side, ensuring suitability of the unit with use on all typical industry refrigerants.

The sensor technology utilises a hermetically welded, dry thin film measuring cell to provide an extremely long-term leak tightness rating. Additionally, these efficient cells are manufactured with a sputtering technique, featuring very long-term stability and a high burst pressure rating.

The manufacturing of these sensors takes place on highly flexible production lines, allowing us to offer customers an unbeatable price-performance ratio with OEM usage.

 

Refrigerant Sensor Technical Specifications

The typical technical specifications of choice on the R-1 pressure sensors includes:

  • Pressure Ranges – gauge pressure ranges from 0 to 6 BAR up to 0 to 2,400 BAR and vacuum (compound) ranges from -1 to +7 BAR up to -1 to +45 BAR.  
     
  • Output Signal – including 4 to 20 mA Current, 1 to 5 V and 0 to 10 V Voltage and 0.5 to 4.5 V Ratiometric.
     
  • Voltage Supply – ranging from 7 to 30 VDC (depending on output signal).  
     
  • Process Connections – including G1/4”, 1/8” NPT, 1/4” NPT, R1/4”, PT 1/4”, 7/16-20 UNF-2A Taper 90° and UNF-2B Schrader Female as standard options.
     
  • Electrical Connections –  including M12 x 1 (4-PIN), Metri-Pack Series 150 and IP69K Cable Outlets as standard options.
     
  • Temperatures – from -40 to +100°C Media and -25 to +85°C Ambient/Storage.
     
  • Accuracy – ≤2% of Span and ≤0.3% Long-Term Drift of Span per year. Accuracy includes non-linearity, hysteresis, zero offset and end value deviation (corresponds to measured error per IEC 61298-2).
     
  • Materials – Case, Wetted Sensor and Process Connection all constructed from Stainless Steel. Electrical connections from highly resistant, glass-fibre reinforced plastic (PBT GF 30).  
     
  • Approvals – options including EC declaration of conformity, UL, EAC, GOST, CRN, TZW and more.  
     
  • Special Options – on request, such as Private Labelling for OEM customers.

 

Thin Film Sensing Technology

There are many different pressure sensing technologies available on the marketplace today. Thin film sensors are one of the most commonly produced sensor technologies by manufacturers across the world.

Sputtered film deposition (or “thin film”) creates sensors with maximum combined linearity, hysteresis and repeatability. Accuracy can be as high as 0.08% full scale with long term drift as low as 0.06% full scale per year.  Phenomenal performance for critical instruments – our sputtered thin film sensors are the jewels of the pressure sensing industry.

Thin film sensors are based on the same principle as strain gauges, which are grid-type resistance structures whose geometric stretching and compression result in a measurable resistance change due to length and thickness differences induced. Typically for a thin-film sensor, four resistors are arranged on a diaphragm in the form of a Wheatstone bridge to detect the deformation of the diaphragm under pressure. In the ‘thin film process’, these strain gauges are attached onto a (e.g. metallic) base element and structured (sputtering with associated photolithography and etching).

For further information on the other types of pressure sensing technologies we can offer, including CVD, Capacitance and MMS types, please click here to visit our blog and explore all the different options available.

 

Equipment for Refrigeration Systems

Within the refrigeration cycle and its periphery there are many points where pressure and temperature are measured and monitored. This serves to control the plant in order to guarantee a secure process run.

Some of the measuring tasks can include indication of pressure and temperature in the lines of the refrigeration cycle on one of the main aggregates, control of fan speed or expansion valve speed, respectively, filter monitoring, temperature measurement in the cooling room, level measurement of pressure vessels or valve control.

In addition to the multitude of applications, the size of the refrigeration system and the refrigerant media itself all place particular demands on the instruments. Here we can help serve you as a competent partner for measuring instruments for pressure, temperature and calibration in all parts of refrigeration plants. Our product offering includes:

  • Mechanical Dial Pressure Gauges for Visual Indication
  • Electrical Contact or Output Pressure Gauges
  • Pressure Sensors for Remote Monitoring and Control
  • Sensors, Switches, Resistance Thermometers and Thermowells for Temperature Measurement

Refrigeration Equipment

Considerations for Refrigeration Engineers

In view of the increasing requirements on refrigeration plants due to new refrigerants or leak-free systems, the quality requirements for measuring instruments are also increasing. Thus, the right choice of materials is critical to get the best possible instruments for the job. Considerations for refrigeration engineers can include:

  • Case Type - choosing the right materials that determines the quality of the case means taking parameters such as pressure, temperature and field conditions into account. The refrigerant itself is not usually a consideration here, as the case is often not a media wetted component. We typically offer a range of plastic, brass and stainless steel cases as standard.
     
  • Wetted Metal Parts - the main deciding factor here would typically be the refrigerant media. You would need to know whether the refrigeration plant is operated with an (H)FCKW/HFKW refrigerant or with ammonia. If it is ammonia, the pressure element must be made of stainless steel (e.g. 1.4571, 1.4404). If it is an (H)FCKW/HFKW refrigerant, a copper-zinc-alloy (brass) is usually sufficient. The same is true for the pressure connection, the thermowell and the stem of the thermometer (any parts that will come into direct contact with the media).
     
  • Thermowells – specific to temperature measurement, if the instrument is not put into the process directly – which is always advisable because of the protection and exchangeability of the measuring instrument – but via a thermowell, various steels are suitable for this protective case. We typically offer stainless steel 1.4571 as standard for thermowells.
     
  • Sealings - the process media, which comes into direct contact with the sealing material, as well as the pressure and temperature are decisive factors for the selection of the suitable sealing material for any o-rings or separating diaphragms. Specially formulated elastomer compounds are most widely used. As standard, we typically offer the materials NBR (acrylonitrile butadiene rubber), FPM (fluor propylene rubber) or EPDM (ethylene propylene diene monomer rubber). We can also offer as an option FFPM (perfluor propylene rubber) or CR (chloroprene rubber) on request.

 

Pressure Sensor Suppliers Near Me

We have a broad selection of pressure sensors featuring an extensive range of options, technologies and configurations to meet almost any application. To explore our full range of pressure sensing solutions, please visit our category page here.

For technical support on selecting the right sensor for your application, get in touch with our experienced engineers here. Alternatively, you can also visit our blog for some introductory guidance on how to correctly select a pressure sensor by clicking here.

Looking for a fast delivery? To view our selection of standard industrial pressure sensors that are available from stock for next-day delivery, click here to see our intuitive part number configuration.