The Savory Taste of Smart


When I was a kid, everyone who grilled had one of those classic round charcoal grills. I remember the mess and the smell of the charcoal and lighter fluid. It took a fair amount of babysitting, but you could achieve great-tasting results. Our family eventually moved on to the convenience of propane, but we sacrificed the quality of the finished product. I recently joined the grilling movement and obtained a pellet grill. It’s one of the models with a programmable controller and wireless interface. After two seasons, it’s here to stay.

Marrying modern technology with the proven process of burning wood is a win! I can program the grill to run a sequence for any given cut, and it turns out fantastic. The best part is that while the device takes care of the cooking business, I can safely get the lawn cut or do other tasks around the house. Are you aware of similar jumps in technology for devices in processing plants? Can they be used to face challenges in the modern business climate like doing more with less people – or getting more product with fewer hours and less downtime? There are smart devices that, like a new pellet grill, can give superior results.

At Interstates we use devices designed with HART protocol, a standard for analog devices that allows plants to communicate multiple process values back from each device over a single 4-20mA wire. The advantage to devices with this protocol are really unlocked when paired with analog input or output cards that are also HART-enabled. If you’re not familiar with the technical specifics of HART, please see this piece written by one of Interstates Engineers, What is HART?

Some of the advantages of using HART devices and I/O include:

  1. Multiple parameters from a single device (e.g. flow, pressure, temperature, totalization, runtime, etc.) brought into the Programmable Logic Controller or Distributed Control System.
  2. Remotely accessing and adjusting devices in hazardous areas.
  3. Receiving instrument diagnostics

HART and other Fieldbus protocols were developed in the 1980’s and have been widely adopted; many manufacturers are now specifically designing devices to take advantage of this advanced communication with the control system.

Examples include:

  • Electronic Differential Pressure (DP) Transmitters. A common application for these transmitters is the replacement of dual capillary level transmitters on pressurized or vacuum vessels. Using an electronic Differential Pressure with HART allows you to know both the gauge/absolute pressure at both sampling points as well as the differential pressure between the points, and the added information can help tune the system or monitor important alarm levels.
  • Mass Flow Meters. HART-enabled flow meters can relay the mass flow, volumetric flow, and density of a product all at the same time. This shows not only how full the tank is, but also the quality of its contents.
  • Superheated Steam Flow Meters. Since proper calculation of superheated steam requires knowing the pressure and temperature of the steam, smart meters can do the calculation internally and relay the corrected flow, pressure, and temperature back to the control system. Additional transmitters or cumbersome flow computers don’t have to be installed.
  • Control Valve Positioners. Positioners already improve control and reduce hysteresis, but adding HART-enabled position feedback will provide solid information about the valve’s actual position.
  • Flow Meters with Self Diagnosis (Heartbeat). Devices like flow meters, pressure transmitters, and level transmitters are now able to provide status on their health and effectiveness. Conditions like tube wear, scaling, build-up, or component failure are constantly monitored and communicated, allowing for schedule maintenance when it makes sense (and when it’s less expensive).

If you want more advice on using smart devices – or if you just need a new BBQ recipe to try – feel free to reach out and let us know how we can help. Give us a call at 712.722.1664.

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Eric Oordt, Interstates Instrument Engineer