New test rooms enable valve testing with ± 5 µm accuracy

In 2015, Festo AG & Co. KG opened the Scharnhausen Technology Factory: at the "Impulsgeber for the Automation of the Future," as the company calls the site, the latest technology is developed using state-of-the-art methods. The focus of the plant is on the production of valves and valve islands. (Source: Festo AG & Co. KG)

To ensure the quality of the products, they are subjected to comprehensive function and durability tests on-site, which are carried out in specially constructed measurement rooms designed for this purpose. (Source: Festo AG & Co. KG)

The system should be installed beneath a visitor platform and the overhang should be equipped with a pitched roof for aesthetic reasons. Additionally, a large viewing area was planned, allowing interested visitors to get an overview of the facility. (Source: Festo AG & Co. KG)

The system should be installed beneath a visitor platform and the overhang should be given a pitched roof for aesthetic reasons. Additionally, a large viewing area was planned, allowing interested visitors to get an overview of the facility. (Source: Festo AG & Co. KG)

To ensure continuous climate stability, walkable sluices have been integrated additionally. Currently, a measurement accuracy of 5 – 7 µm can be achieved. (Source: Festo AG & Co. KG)

As part of the measurement room realization in Building 55 – the new construction – a new demand arose in Building 50. Therefore, Nerling received another order for a measurement room. (Source: Festo AG & Co. KG)

"Our strength lies in comprehensively understanding customer problems, jointly developing solutions with the customer, and implementing them with our proven technology," confirms Olaf Nerling, Managing Director of Nerling Systemräume GmbH. (Source: Nerling Systemräume GmbH)

To ensure the quality of their valves, Festo AG & Co. KG conducts comprehensive functional and durability tests across all their product lines. However, in order for the highly sensitive measuring devices to achieve the required accuracy of ± 5-7 µm, only minimal temperature and humidity fluctuations are permitted in the immediate measurement environment. For this reason, Festo commissioned Nerling Systemräume GmbH in 2014 to build two specially adapted measurement rooms as well as an attached measurement equipment room for storing small parts. One of the facilities, which meets the requirements of quality class 2, was planned to be integrated into an existing hall. The other was to be built—in the colors of the corporate identity—for maximum external impact—under a visitor platform in the new main building. The measurement room with quality class 3 was additionally to be equipped with a wide viewing area, requiring precise planning of the utility lines. The rooms have been in operation since 2015 and guarantee stable climate conditions with a maximum deviation of ± 1.0 K/h and a relative humidity between 40 and 60 percent.

At the "impulse generator for the automation of the future," as the company calls the site, the latest technology is developed using state-of-the-art means. The focus of the plant is on manufacturing valves and valve islands. To ensure product quality, they are subjected to comprehensive functional and durability tests on-site, which are carried out in specially constructed measurement rooms. "In the past, we used semi-conditioned rooms for this purpose. However, the drafts caused by air conditioning affected the measurement results," explains Rainer Hermann, head of measurement and testing technology at Scharnhausen, Festo. "Therefore, we decided to commission a measurement room from Nerling Systemräume GmbH."

Planning Incorporating Individual Requirements

"Festo involved us early in the planning because the measurement room was part of the new plant concept," recalls Olaf Nerling, managing director of Nerling Systemräume GmbH. Specific requirements were set for the space used for serial support of machining and assembly: The measurement room of quality class 3 was to be built in the new building complex in Scharnhausen. The order also included a measurement equipment room, where fine probe balls (smallest diameter 0.25 mm) or probe elements are stored, which are used for measurements in holes, on surfaces, and partly also on freeform surfaces in scanning procedures.

"The facility was to be installed under a visitor platform and the overhang was to be covered with a roof pitch for optical reasons. This required precise media planning to accommodate all components and supply lines in the suspended ceiling," notes Nerling. Additionally, a large viewing area was planned to give interested parties an overview of the facility. For a more prominent external appearance, Festo also wanted the rooms to be finished in the colors of their corporate identity.

Sensitive Measuring Devices Require Climate-Stable Rooms

"Our measuring devices place high demands on their environment: they require a reference temperature of 19 – 21 °C and a relative humidity of 40 – 60 percent," Hermann explains. These requirements correspond to quality class 3 of VDI/VDE 2627. Accordingly, the temperature gradients for the measurement room were uniformly set to: 1 K/h, 2 K/d, and 0.5 K/m. Initially, Nerling planned to use a chilled water network installed during the hall construction for cooling the measurement room. However, when the delivery and installation took place as scheduled in spring 2015, it became apparent that the promised properties at the transfer point could not be realized, leading to temperature issues within the measurement room. "Together with all involved parties, solutions were developed that now ensure stable temperature behavior," Nerling explains. To guarantee continuous climate stability, additional walk-in airlocks were integrated. Currently, a measurement accuracy of 5 – 7 µm can be achieved.

In total, exclusively tested Nerling systems and components were used, which had to be partially adapted to local conditions. "Our strength lies in thoroughly understanding customer problems, jointly developing solutions with the customer, and implementing them with our proven technology," Nerling affirms. This also includes the installed PLC: Due to the high demands not only regarding temperature stability but also humidity control, an individual control system was required. Therefore, the system room expert opted for a freely programmable, central PLC with Nerling software. Via a 15-inch touchscreen, integrated into a wall of the room system and displaying relevant parameters, all climate components, including supply air, can be conveniently controlled. Additionally, fault messages can be issued, and remote maintenance can be performed via a module. "So far, the control system has proven to be low-maintenance and reliable," Hermann reports with satisfaction.

Second Measurement Room Commissioned

Even before the first project was completed, Nerling was able to secure an additional order: "During the realization of the measurement room in Building 55—the new construction—another need arose in Building 50," Nerling describes the situation at the time. For this problem, a joint search for the optimal implementation was conducted, and a suitable location was quickly found: It was unsuitable as a production area but could be used without issue for the measurement room expansion. Thus, another measurement room was created, which in this case meets quality class 2." "The challenge in this case was that all technology had to be housed behind panels within the measurement room itself," the managing director continues. Ultimately, all necessary components were positioned on a technical pedestal inside the room.

The measurement rooms underwent a four-week testing phase, which they passed without issues. Festo rates the collaboration on this joint project as pleasant: "Particularly the customer-friendly service and prompt solutions will remain positively in our memory," Hermann concludes.