Special samplers are used for the active collection of airborne microbes in highly sensitive cleanroom areas for maximum protection of people and materials. For simple and largely contact-free handling of the structure, the British company Pinpoint Scientific, which specializes in laboratory equipment, uses hydraulic brake cylinders from ACE Stoßdämpfer GmbH.

Microbiological environmental monitoring is regulated via ISO Guideline 18593. A leading company for a range of specialist laboratory equipment products is Pinpoint Scientific, based in Bridgend in Wales, UK. Its product range includes solutions for air monitoring, continuous monitoring of viable particles and monitoring solutions for isolators. Quality sampling for laboratory personnel includes ease of use and effective contamination control. The ImpactAir range of microbial air samplers from Pinpoint Scientific can also be seen as a prime example of a solution that has been thought through down to the smallest detail. They are designed for continuous monitoring in research and industrial laboratory environments where in-process sampling of viable particles is critical. The work is accomplished by drawing air at high velocity through a very narrow inlet slot, whereupon particles, including microbes in the air, impinge on and adhere to an applied culture surface in a Petri dish. The Petri dish is slowly rotated under the inlet to ensure that the air always impinges on a fresh area of the culture. This drastically reduces the likelihood of double impingement. This is a microbiological and physical phenomenon in which two microbes land at the same point and appear as a single colony during incubation. In order to make the work of the users as easy as possible, especially in clean room environments of laboratories in the food or medical industry as well as in the pharmaceutical industry during sampling, the designers of Pinpoint Scientific turned to a UK distributor of ACE shock absorbers GmbH during their search for high-quality components for velocity control. After considering all the requirements and requests, he recommended hydraulic brake cylinders made in Germany to operate the hood.

Hydraulic brake cylinders for special solution



Wyn Gordge, one of the sales engineers of ACE in Great Britain, describes the initial situation: "With our distributor, the company Applied Automation, we have already cooperated successfully many times, so that a supply also in this case led quickly to the desired result on the customer side."He describes the customer's wish for an opening process of the sampler hood without any significant effort as the decisive point for the use of hydraulic brake cylinders. Without this requirement, ACE's stainless steel industrial gas springs, which can be precisely adjusted to the desired opening and closing speed by means of a valve, would in principle also have been suitable as machine elements. But because, in contrast to the visually very similar industrial gas springs, the hydraulic brake cylinders of the HB15-50 type only have to be tapped to trigger the opening process of the hood, the choice fell on these components, which ACE has available in the area of speed regulation. Another plus in this application is the feature that these brake cylinders allow a smooth closing process with additional damping.

ACE as an expert brand of the Stabilus Group and Applied Automation as an experienced distributor of components for laboratory technology were able to show another strength. Known as a development partner and appreciated for customized solutions even for small quantities, ACE managed a masterpiece of hydraulics: Since the ImpactAir samplers are mostly used in critical laboratory environments and clean rooms, the use of machine oil as damping medium in the body of the brake cylinder was out of question according to Pinpoint Scientific's specifications. Because of this requirement and the sensitive nature of the application, ACE selected a special vegetable oil with very similar viscosity and service life. In the course of the product design, Pinpoint Scientific's design engineers then added stainless steel sleeves to encase the hydraulic brake cylinders, whose outer bodies are made of coated steel as standard. On the one hand, this measure serves to meet the high hygiene requirements for operation in clean rooms; on the other hand, the stainless steel material of the sleeves perfectly matches the overall design of the ImpactAir-140.

The machine elements used from ACE are ideally suited for opening the hood and holding it at an opening angle of 60 degrees as required, thanks to their infinitely variable adjustability of the pressure or tensile force between 20 N and 800 N. The machine elements can also be adjusted to any desired position. Adjustment of the double-acting or single-acting hydraulic brake cylinders is simply made via the adjustment segment on the piston. Due to their high quality and long service life, there is hardly any limit to the wishes of end customers in the laboratory sector with regard to the frequency of opening and closing operations, as Pinpoint Scientific explains. Otherwise, these machine elements for the precise regulation of speeds are primarily used in a wide variety of automotive or industrial designs, but also in the electronics, furniture and leisure industries.