Diaphragm Seals Protect Industrial Pressure Gauges and Transmitters

industrial pressure gauge with diaphragm seal installed
Industrial pressure gauge with diaphragm seal installed
Courtesy Wika
Pressure measurement is a common element of industrial operations and control systems. Fluid processing can often involve media that is potentially harmful to pressure sensing devices. The media may be corrosive to the sensor material, or other media properties may impact the performance or usable life of the instrument. In process control environments, diaphragm seals play a role in protecting items like pressure sensors from damage by process fluids. The diaphragm seal is a flexible membrane that seals across the connecting path to a sensor and isolates the sensor from the process media. System pressure crosses the barrier without inhibition, enabling accurate measurement, but the process fluid does not. Typical materials composing diaphragm seals are elastomers, with a wide variety of specific materials available to accommodate almost every application.

In the operating principle of the diaphragm seal, the sealed chamber created between the diaphragm and the instrument is filled with an appropriate fluid, allowing for the transfer of pressure from the process media to the protected sensor. The seals are attached to the process by threaded, open flange, sanitary, or other connections. Diaphragm seals are sometimes referred to as chemical seals or gauge guards. Stainless steel, Hastelloy, Monel, Inconel, and titanium are used in high pressure environments, and some materials are known to work better when paired with certain chemicals.

Sanitary processes, such as food, beverage, and pharmaceuticals, use diaphragm seals to prevent the accumulation of process fluid in pressure ports, a possible source of contamination. If such a buildup were to occur, such as milk invading and lodging in a port on a pressure gauge, the resulting contamination compromises the quality and purity of successive batches. Extremely pure process fluids, like ultra-pure water, could be contaminated by the metal surface of a process sensor. Some pneumatic systems rely on the elimination of even the smallest pressure fluctuations, and diaphragm seals prevent those by ensuring the separation of the process materials from the sensors.

Diaphragm seals are not without some application concerns, and devices are now built to address and counter many potential issues related to the use of diaphragm seals with process monitoring instruments and equipment. Products seek to eliminate any and all dead space, allow for continuous process flow, and are self-cleaning thanks to continuous flow design. Some high pressure seals come equipped with anti-clogging features, accomplished by the elimination of internal cavities while protecting gauges. Multi-purpose seals reduce temperature influence and improve instrument performance while pinpointing and diffusing areas of high stress. These pre-emptive measures result in longer instrument life-cycles and improved performance while ensuring protection from corrosion.

There are numerous options and available diaphragm seal variants. Share your application specifics with a product specialist, combining your own process knowledge and experience with their product application expertise to develop an effective solution. Analynk Wireless manufactures industrial wireless communications equipment and process transmitters.

Tachometer Transmitter for Industrial Process Measurement and Control

industrial motor pump assembly
Tachometer transmitters deliver rotational speed signals
Analynk Wireless, in addition to producing their line of products for establishing wireless connections among industrial process measurement and control devices, manufactures an extensive array of wired products. The wired products are useful in establishing similar connections between sensors and the devices or instruments that will utilize their output signals. The transmitters are available with a wide array of input and output combinations, as well as several enclosure options. Enclosures can be customized to meet specific installation challenges.

The tachometer transmitter will convert the pulse signal from a tachometer into a linear signal representing rotational speed. There are many applications where a frequency output from a tachometer or other sensor needs conversion to a 4-20 mA or other common signal for use by a monitoring instrument. Analynk provides transmitters to easily convert almost any sensor signal to a linear voltage or current output. A data sheet is included below that provides more detail about one of the many transmitters available from Analynk.

Share your connectivity challenges with the process signal transmission experts at Analynk. Effective solutions come through consultation and cooperation.


Antennas In Industrial Wireless

explosion proof antenna for industrial wireless communications in hazardous areas
Explosion proof antenna for industrial wireless
communications in hazardous locations
Analynk Wireless
Wireless field instrumentation has played a growing role in the process control industry since its introduction. Digital instrumentation has become the industry standard thanks to advantages in communicability, durability, cost effectiveness, and integration. WirelessHART maintains, and even exceeds, the operating efficiency of wired systems without sacrificing security. Other protocols for industrial communications also operate in the process control space, each providing an operable solution for wireless connectivity. All utilize a common signal path that is worth understanding, if you are involved in process measurement and control…radio

Communicating information over long distances through open space is achieved by radio systems using electromagnetic fields. The common radio wave comprises oscillating electric and magnetic fields to generate electromagnetic radiation. The three most common antenna designs are the half-wave dipole antenna, the quarter-wave whip antenna, and the five element yagi antenna. The dipole and whip antennas are engineered to adeptly receive electromagnetic waves from all directions perpendicularly aligned with their axes. The yagi antenna, on the other hand, boasts director and reflector elements to increase its directionality. Thanks to this directionality, the yagi is best applicable in radar and point-to-point communications. The dipole and whip, also known as omnidirectional antennas, are better in situations where equal sensitivity is required in multiple directions instead of a pinpoint system.

Supervisory control and data acquisition (SCADA) systems find uses for both yagi and dipole antennas. The dimensions of particular antennas are directly related to signal wavelength because radio antennas work at maximum efficiency when in conditions of electrical resonance. The actual size of the antenna allows for a certain electrical resonance frequency. Low frequency antennas are larger, and higher frequency antennas are smaller. A quarter-wave whip antenna designed as part of a 900 MHz transceiver application, in industry, would be around 8.3 centimeters. The same antenna design for an AM radio broadcast transmission operating at 550 KHz would be around 136 meters. These antenna parameters are specific to both the conditions the antenna operates under and the related frequency being measured.

Industrially designed yagi antennas are built to preserve the reliability of wireless monitoring, even in harsh environments. Oil and gas companies, water districts and progressive utilities can monitor Remote Terminal Units (RTUs) from a centralized location. The major challenge facing radio wireless monitoring today is the maximization of uptime in difficult environments. The challenge is being addressed by the development of antennas which can pair with National Electrical Manufacturers Association RTU enclosures. Protecting against dust and rain, wind, splashing water, and hose-directed water are some of the ways product developers are responding to industry reported client concerns. Additionally, industrial environments can present hazards that require the use of specially enclosed antennas to eliminate the potential for ignition of flammable atmosphere. Similarly, dipole antenna manufacturers are adapting to challenging environments by designing antennas specific to the application needs of industry customers.

Analynk Wireless provides solutions for establishing wireless connections in industrial settings. You can learn more about the company at their website.

Install Aruba AP-324 Wireless Access Point in Hazardous Area


wireless access point enclosure for hazardous location
Analynk AP619 wireless access point enclosure
Analynk Wireless expands its already extensive line of wireless access point enclosures for hazardous industrial locations. The recent addition is the model AP619, specially equipped to house the Aruba AP-324 dual band access point.

Analynk access point enclosures accommodate specific wireless access points from a range of manufacturers, facilitating easy installation. Every model includes UL listed explosion proof antennas, a mounting bracket custom tailored for the access point equipment, and RF cables to make the antenna connections. Enclosures have penetrations located to match up with the specified access point. Models are included to house a range of units from Symbol, Cisco, Meru, Aruba, HP, and Motorola, with more models added regularly to accommodate additional wireless access points.

 Analynk Wireless specializes in industrial wireless communications. Your wireless communication challenges are welcome at Analynk, so make contact and share your requirements. Combining your process expertise with Analynk's product specialization will produce an effective solution.

The datasheet for the new model is provided below. You can see all the models and their companion access points on the Analynk site.


Video From Analynk Wireless



Analynk Wireless manufactures equipment used to establish wireless connections among process measurement and control devices. Receivers, transmitters,repeaters, antennas, and other devices can be used to easily establish connections between standard industrial process control instrumentation. Single and multiple point installations can be accommodated. Analynk also provides wireless access point enclosures and antennas for hazardous locations.

Analynk gear enables customers to create wireless connections across the room, across the street, and across the globe. Share your wireless connection ideas and challenges with the experts at Analynk. The combination of your process knowledge and their wireless communication expertise will lead to an effective solution.

Wireless Transmitters In Process Measurement and Control

power plant with wireless process control
Opportunities for cost effective wireless process control
connections are everywhere
In process control, different devices produce signals which represent flow, temperature, pressure, and other measurable elements of the control process. In order to travel from the measurement point to the point of decision, also known as the controller, systems have traditionally relied on wires. More recently, wireless networks used in industry have evolved, especially since point-to-point systems were introduced to process environments. The standard operating procedure today is known as the Wireless HART™ protocol, which features the same hallmarks of control and diagnostics featured in wired systems without an accompanying wire.

Wireless devices and wired devices can cohabitate the same network. The installation costs of wireless networks is vastly lower than wired networks due to the fact wireless networks need much less hardware. Wireless networks are also more efficient than their wired peers in regards to auxiliary measurements, involving measurement of substances at several points. Adding robustness to wireless, self-organizing networks is easy, because when new wireless components are introduced to a network, they can link to the existing network without needing to be reconfigured manually. Gateways can accommodate between 50 and 100 devices, allowing a very elastic range for expansion.

In a coal fired plant, plant operators walk a tightrope in monitoring multiple elements of the process. They calibrate limestone feed rates in conjunction with desulfurization systems, using target values determined experientially. The difficult process environment results from elevated slurry temperatures, and the associated pH sensors can only last for so long under such conditions. Thanks to the expandability of wireless transmitters, the incremental cost is reduced thanks to the flexibility of installation of new measurement loops. In regards to maintenance, the status of wireless devices are consistently transmitted alongside the process variables. Fewer manual checks are needed, and preventative measures are infrequent compared to wired networks. The minimization of overtime and staff instruction correlates with a maintenance of precise process control.

Time Synchronized Mesh Protocol (TSMP) ensures perfect timing for individual transmissions, which lets every transmitter’s radio and processor ‘rest’ between either sending or receiving a transmission. To compensate for the lack of a physical wire, in terms of security, wireless networks are equipped with a combination of authentication, encryption, verification, and key management. The amalgamation of those fail-safes makes for the security of wireless networks equal to that of a wired system. The multilayered approach, anchored by gateway key-management, presents a defense sequence. Thanks to the advancements in modern field networking technology, interference due to noise from other networks has been minimized to the point of being a rare concern. Even with the rarity, fail-safes are included in Wireless HART™.

All security functions are handled by the network autonomously, meaning manual configuration is unnecessary. In addition to process control environments, power plants will typically use two simultaneous wireless networks. Transmitters allow both safety showers and eyewash stations to trigger an alarm at the point of control when activated. Thanks to reduced cost, and their ease of applicability in environments challenging to wired systems, along with their developed performance and security, wireless instrumentation is altering process control environment monitoring for the better.

Analynk Wireless specializes in making wireless connections among process measurement and control equipment in the industrial arena.

Standalone Process Temperature Controllers

industrial control panel
The regulation of temperature is a common operation throughout many facets of modern life. Environmental control in commercial, industrial, and institutional buildings, even residential spaces, uses the regulation of temperature as the primary measure of successful operation. There are also countless applications for the control of temperature found throughout manufacturing, processing, and research. Everywhere that temperature needs to be regulated, a device or method is needed that will control the delivery of a heating or cooling means.

For industrial process applications, the temperature control function is found in two basic forms. It can reside as an operational feature within a programmable logic controller or other centralized process control device or system. Another form is a standalone process temperature controller, with self-contained input, output, processing, and user interface. Depending upon the needs of the application, one may have an advantage over the other. The evolution of both forms, integrated and standalone, has resulted in each offering consistently greater levels of functionality.

There are two basic means of temperature control, regardless of the actual device used. Open loop control delivers a predetermined amount of output action without regard to the process condition. Its simplicity makes open loop control economical. Best applications for this type of control action are processes that are well understood and that can tolerate a potentially wide variation in temperature. A change in the process condition will not be detected, or responded to, by open loop control. The second temperature control method, and the one most employed for industrial process control, is closed loop.

Closed loop control relies on an input that represents the process condition, an algorithm or internal mechanical means to produce an output action related to the process condition, and some type of output device that delivers the output action. Closed loop controllers require less process knowledge on the part of the operator than open loop to regulate temperature. The controllers rely on the internal processing and comparison of input (process temperature) to a setpoint value. The difference between the two is the deviation or error.  Generally, a greater error will produce a greater change in the output of the controller, delivering more heating or cooling to the process and driving the process temperature toward the setpoint.

A standalone temperature controller can fulfill multiple functions. In addition to controlling the target process temperature, controllers can be configured with data logging, alarm outputs, programmed changes to setpoints, auxiliary outputs for on/off functions, and a detailed HMI to provide data entry or a display of the process condition. Locating the controller near the process can be useful when technicians or operators need to monitor the process or effect a change in the controller setpoint. Local controllers can be connected via wired or wireless communications to other monitoring and control devices. Wireless communications are easily accomplished using Analynk's transmitters and receivers to cover distances from inches to miles.

The current product offering for standalone closed loop temperature controllers ranges from very simple on/off regulators to highly developed products with multiple inputs and outputs, as well as many auxiliary functions and communications. The range of product features almost assures a unit is available for every application. Evaluating the staggering range of products available and producing a good match between process requirements and product capabilities can be facilitated by reaching out to a process control products specialist. Combine your own process knowledge and experience with their product application expertise to develop effective solution options.