This article was originally published on October 7, 2014.
When a surface-treatment company adds data logging, they gain run-time data.
Northeast Coating Technologies (NCT) in Kennebunk, Maine, is a surface-treatment company specializing in salt-bath nitriding, Melonite® QPQ and other processes to produce high-durability metal components including piston rods, axles and more.
The Melonite QPQ process forms a nitrocarburized layer around components comprised of an outer compound layer (iron, nitrogen, carbon and oxygen compounds) and a diffusion layer underneath. Initially, the process preheats components to raise their surface temperature before they are placed in a tank containing liquid Melonite salt to start the nitrocarburizing process. Alkali cyanate is the active constituent in the salt bath, and this step is regulated at 896-1166°F (480-630°C) with a standard temperature of 1076°F (580°C).
The components react with the salt and start to diffuse nitrogen and carbon into the substrate. After a preset period of 1-2 hours, the components have the proper compound layer thickness and case depth. After immersion in the salt bath, the components are placed in a cooling bath maintained at 700-800°F (371-427°C) for oxidative treatment, which forms a magnetite layer on the components to improve corrosion resistance.
Tank temperature is the treatment parameter NCT needed to monitor and trend for each of its three Melonite salt tanks and the oxidizing-bath tank. With this in mind, CAS DataLoggers of Chesterland, Ohio, provided the facility with a Series 3 dataTaker universal data logger to automate their data collection.
Conrad Woodman installed the dataTaker DT80 Intelligent Universal Data Logger in a control cabinet located about 30 feet away from the salt-bath tanks. For future expansion, the panel size is large enough to add a touchscreen PC running Windows 7 embedded in the face of the control panel. Another junction box is set up between the tanks and the dataTaker where the cables run.
Woodman uses the instrument to continually monitor NCT’s production Melonite QPQ line, specifically the salt-bath area. Tank temperatures from multiple thermocouples are monitored, and these readings are used to trend the run data to prove best practices to customers.
NCT is currently collecting temperature data from four type-K thermocouples. All four sensors run to different tanks in the same area. Three take readings from each of the three Melonite tanks, and one sensor goes to the oxidizing tank. In the future, NCT may use a dataTaker CEM20 channel-expansion module and run thermocouples from their oven and degreaser tank, enabling them to cover six monitoring points using the same system. Using multiple monitoring schedules, several tanks are simultaneously monitored. The stand-alone logger also features a built-in display and operates reliably using low power.
Users simply input an IP address in a web browser when they need to retrieve the temperature data. Woodman has set up a link on the desktop PC located in the nitriding area so users can export the data in CSV format and work with it in Excel. The dataTaker can store up to 10 million data points in its user-defined memory, enabling independent control of schedule size and mode so that it can be set up to log only as long as needed. Users can also retrieve data from a flash drive via the USB port.
E-mail Alarm Notification
The dataTaker doubles as an automated alarm system, giving users a quick way to tell if a potentially critical situation is developing. The e-mail alert feature will notify Woodman and other users if there is an issue with the salt bath (e.g., if tank temperature starts boiling over and threatens to eventually cause a fire). The temperature alarm is set to send out an e-mail alert that the process is malfunctioning whenever any tank temperature goes over 1250°F (677°C). Workers are then able to take immediate remedial action to prevent damage and delays.
Using DPlot software, users display the data by going into the thermocouple sensor page and convert it into CSV format. Users can also view the high and low range for each sensor, and it’s equally easy to open up the DBD files and plot them into a graph for presentation. DPlot is included with every dataTaker data logger.
Using included dEX software, users can create dashboard dials to view real-time data, create trend charts and tables, and retrieve historical data for analysis. The Windows Explorer-type interface makes navigation easy. This built-in software runs directly from a web browser and can be accessed locally or remotely anywhere that a TCP/IP connection is available, and both DPlot and dEX software run in Windows 8.
The DT80 data logger helps NCT prove that their nitriding process achieves a consistent nitride layer on all components. Not only can this single solution connect to type-K thermocouples on all four tanks, but it can also connect with any sensor to measure nearly any value. The system’s ease of programming and large internal memory give users an effective data-trending solution. NCT can now provide customers detailed runtime data that shows their best practices.
All the data is easy to organize and present in Excel. Woodman explained, “We have the dataTaker logger up and running seamlessly. We had a couple hiccups originally in the programming aspect of it, but we quickly got through them since you don’t have to be an engineer to learn the software. This unit is exactly what we needed for the process we are using it for.”
As a secondary benefit, NCT can also rely on the e-mail alarm feature for additional process overview. Due to its flexible programmability, the unit is set up to track both the runtime and alarming.
Woodman has also received free tech support from CAS DataLoggers over the phone to get the project set up ASAP.
Applications Specialist Pat Picciano said, “The dataTaker’s software is internal, so everything this application needs is there in the unit itself. It has the memory, the data-trending capability and the alarming feature. That’s why the DT80 is our workhorse.” IH
For more information: Contact an applications specialist at CAS DataLoggers, Inc., 12628 Chillicothe Road, Chesterland, Ohio 44026; tel: 440-729-2570; toll-free: 800-956-4437; e-mail: firstname.lastname@example.org; web: dataloggerinc.com