Microbiological environmental monitoring is regulated by ISO 18593. A leading company for a range of specialist laboratory technology products is Pinpoint Scientific from Bridgend in Wales, UK. The product range includes solutions for air monitoring, continuous monitoring of viable particles and monitoring solutions for isolators. Quality sampling for laboratory staff also includes ease of use and effective contamination protection. The microbial air samplers in the ImpactAir series 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 have been developed for continuous monitoring in research and industrial laboratory environments where in-process sampling of viable particles is critical. The work is carried out by drawing air at high velocity through a very narrow inlet slot, whereupon particles, including microbes in the air, impact 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 where two microbes land at the same point and appear as a single colony during incubation. In order to make the work of users as easy as possible during sampling, especially in clean room environments in food or medical technology laboratories and in the pharmaceutical industry, the designers at Pinpoint Scientific turned to a British distributor of ACE Stoßdämpfer GmbH during their search for high-quality components for speed regulation. After considering all the requirements and requests, the distributor recommended hydraulic brake cylinders made in Germany to operate the hood.

Hydraulic brake cylinders for a special solution

Wyn Gordge, one of ACE's sales engineers in the UK, describes the initial situation: "We have often worked successfully with our distributor, Applied Automation, so that in this case, too, a delivery quickly led to the desired result on the customer side." He describes the customer's desire for the sampler cover to open without any significant effort as the decisive factor in the use of hydraulic brake cylinders. Without this requirement, the stainless steel industrial gas springs from ACE, which can be precisely adjusted to the desired opening and closing speed using a valve, would have been an obvious choice as machine elements. However, in contrast to the visually very similar industrial gas springs, the hydraulic brake cylinders of type HB15-50 have to be tapped to trigger the opening process of the hood, so these components, which ACE offers in the area of speed regulation, were chosen. A further advantage of this application is the fact that these brake cylinders enable a gentle 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 play to another strength. Known as a development partner and valued for customer-specific solutions, even for small quantities, ACE achieved a masterstroke in hydraulics: As the ImpactAir samplers are mostly used in critical laboratory environments and clean rooms, the use of machine oil as a damping medium in the body of the brake cylinder was out of the question according to Pinpoint Scientific's specifications. Due to this requirement and the sensitive areas of application, ACE chose a special vegetable oil with a very similar viscosity and service life. As part of the product design, the engineers at Pinpoint Scientific then added stainless steel sleeves to encase the hydraulic brake cylinders, the outer bodies of which 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 and, on the other hand, the stainless steel material of the sleeves fits in perfectly with the overall design of the ImpactAir-140.

The ACE machine elements used are ideally suited to opening the hood and holding it at an opening angle of 60 degrees as required, thanks to their infinitely variable adjustment of the pressure or tensile force between 20 N and 800 N. The hydraulic brake cylinders, which act on both sides or one side, are easily adjusted using the adjustment segment on the piston. Due to their high quality and long service life, there is hardly any limit to the number of opening and closing operations that end customers in the laboratory sector can request, as Pinpoint Scientific explains. Otherwise, these machine elements for the precise regulation of speeds are primarily used in a wide variety of automotive and industrial designs, as well as in the electronics, furniture and leisure industries.