Why Measure Oven Temperature?

To ensure a successful cure of a powder coating for a quality, long-lasting finish, it is critical to accurately measure the temperature/time profile of the cure oven, particularly when loaded with the components to be cured.

Oven temperature/time profile is influenced by the thermal loading of the oven, therefore it is not sufficient to just set the oven zone controllers to an appropriate temperature value and expect the temperature/time requirements to be met.

An unsatisfactory cure results in a significant reduction in the quality of the final coating in terms of gloss, colour and adhesion. Too high a temperature can burn the coating and too low a temperature, or insufficient time at the required temperature, can result in an incomplete cure.

How to accurately measure an oven temperature

An oven data logger makes taking measurements and capturing the information simple, providing valuable data about the entire coating cure process. An oven logger is a measurement logging device with several connections for thermocouples. It is placed in a box which protects it from the high temperatures involved as it passes through the oven with any components, recording the temperature profile through the oven.

Although commonly known as an ‘oven logger’, it is not the oven temperature that is the critical measurement, but the temperature of the component.

Not all components are alike and there is rarely a uniform density. Therefore, if not adjusted to suit the component being coated, the oven temperature settings may lead to under cure, coating burn, poor adhesion, discolouration, loss of gloss and other visible defects.

By using magnetic or clamp type air and surface temperature probes, temperatures can be monitored both on and around the product and recorded by the data logger, providing valuable information about the time taken to heat the component to the cure temperature and how long this temperature was maintained.

Monitoring and making adjustments to the oven temperature ensures that the product is brought to and held at, the specified temperature to ensure consistent quality of cure and visual properties at all times.

The Elcometer 215 Oven Data Logger

Ideal for testing powder or liquid coatings in batch or conveyor ovens, the Elcometer 215 Oven Data Logger is an easy-to-use, battery powered temperature data recorder that uses up to six K-type thermocouple probes to monitor the cure process. Complete with an efficient thermal barrier kit, the oven data logger is protected from temperatures of up to 250°C for a period of 100 minutes.

Storing up to 260,000 readings, or eight production runs, the oven data logger allows the user to control the cure process for a wide range of products and applications. The data-logging interval can be set by the user from eight readings per second to one reading per hour. The Elcometer 215 also features a menu driven LCD screen which can display individual channel temperatures.

Six different clamp or magnetic K-type thermocouple probes can be connected to the logger simultaneously for measuring surface or air temperatures, with strong, flexible and easy-to-clean, Teflon? coated cables in a variety of lengths. The probes have a continuous maximum operating temperature of 250°C and their low mass and optimised shape eliminates influence on the temperature of the component.

The Elcometer 215 in action

Manufacturers of architectural aluminium fa?ade products, Multi Fab, have recently purchased the Elcometer 215 to use within their conveyor oven to measure the temperature profile of their powder coated aluminum sheetmetal products for the construction industry. The Suffolk based company, who are part of the EAG (English Architectural Glazing) group, are renowned for working on the M&S building in Westfields, Stratford and the BBC building at the Television Centre in London.

Since purchasing the Elcometer 215 Oven Data Logger, Multi Fab have continuously used the product daily, using all six probe connections; two air probes to test the oven temperature and four surface probes to test the temperature of the component to ensure a consistent quality cure and improved finished product. As part of their quality inspection regime, the powder coaters also use ElcoMaster? data management software to manage and assess their oven temperature profile, allowing them to generate professional quality inspection reports in seconds.

It’s what you do with your data that counts

ElcoMaster? is free, easy-to-use data management software ideal for the management and assessment of temperature profile. ElcoMaster? allows the user to create and store unique oven profile setups; name each of the six channels; set sampling rates, number of batch runs and start/stop triggers and transfer them to the oven data logger. When one or more runs have been recorded, the data can be downloaded to ElcoMaster? via USB.

Using the industry accepted cure value calculation; ElcoMaster? also provides instant pass/fail information by comparing the production run temperature to the coating supplier’s cure requirements.

Different powder types can be created and stored in ElcoMaster? by simply entering the cure schedule into the software, creating a custom ‘paint’. This can be downloaded into the logger, ready for batch logging.

Professional inspection reports in seconds

At the click of a button, ElcoMaster? produces fully customisable reports, including the coating type and temperature curve, together with the duration of the drying process at the maximum and minimum cross-linking temperatures. The report will show the probes, the duration of the process and the probe positions. It will also display a simple cure pass/fail calculation from the collected data. The product data sheet, product images and graphics can also be incorporated for a professional, easy-to-read report.