Comde-Derenda GmbH products

The low and medium volume samplers LVS and MVS collect fine particulate matter on sampling filters according to EN 12341:2014 (PM10 and PM2.5). For this purpose, a vacuum pump draws in ambient air, and the sampler fractionates the airborne fine particles in a sampling inlet. The air containing the desired fine particulate fraction then passes through the filter, where the particles are collected and made available for subsequent gravimetric assessment or analysis. The volumetric flow rate is measured with an orifice plate and electronically adjusted with an accuracy of ≤ 2%. Types: LVS 3.1 (Low Volume Sampler) / MVS 6.1 (Medium Volume Sampler).

The PNS T-DM combines a low / medium volume sampler (LVS or MVS) and a filter changer in a stainless steel cabinet. It collects fine particulate matter on sampling filters according to EN 12341:2014 (PM10 and PM2.5). For this purpose, a vacuum pump draws in ambient air, and the system fractionates the airborne particles in a sampling inlet. The air containing the desired fine particulate fraction then passes through the filter, where the particles are collected and made available for subsequent gravimetric assessment or analysis. The automatic filter changer with Geneva drive and two parallel filter magazines facilitates sequential series of up to 18 or 24 sampling cycles. The volumetric flow rate is measured with an orifice plate and electronically adjusted with an accuracy of ≤ 2%. Types: PNS 18T-DM-3.1 / PNS 18T-DM-6.1 / PNS 24T-DM-3.1 / PNS 24T-DM-6.1.

The method applied by the APM-2 uses the light scattered by tiny particles (nephelometry) to determine the PM10 or PM2.5 concentration in the ambient air directly and continuously. After performing a qualification test, TÜV Rheinland certified the procedure as equivalent to the customary gravimetric method. The system features an impactor inlet for fractionating the particulate matter, and a virtual impactor for dividing the air stream into two streams for the alternate, quasi-simultaneous determination of the SPM fractions PM2.5 and PM10.

Climate-controlled automatic weighing system with RFID technology for the gravimetric assessment of sampling filters. The automatic weighing system AWS-1RE provides a precise filter conditioning and weighs up to 750 filters in an automated process. Integrated RFID technology identifies and tracks the filters during the entire process. If a PC is connected, the weighing results are recorded in a database along with relevant ancillary data, such as temperature and relative humidity. Automation contributes to the very high reliability and precision of both weighing and documentation. A weighing chamber with a fan filter unit (FFU) and climate control unit maintains controlled, dustproof conditions throughout the weighing operation. Its modular design allows the system to be adapted to customers’ specific requirements.

Sampling inlets for SPM samplers, sampling systems and real-time monitoring devices. All Comde-Derenda sampling inlets, also known as sampling heads, have been designed and tested specifically for use with our sampling and monitoring systems. They are suitable for measuring various substances, including particulate matter (PM10, PM2.5, PM1 and TSP) and numerous volatile organic compounds (dioxins, furans, PCB, etc.).

Hybrid density monitor for SF6 gas-insulated high-voltage circuit breakers; The Densistat D56Hybrid is suitable for indoor and outdoor use. It incorporates an analog gauge for relative pressure, referenced to 20 °C. The measured values are also provided as a data output signal. Microswitches inside the device respond reliably to any decreases in the density and pressure of the SF6 insulating gas. The pressure connection is either straight or angled (several options are available).

Transmitter for monitoring gas density in SF6 gas-insulated high-voltage systems; The gas density transmitter GDS continuously monitors the pressure and temperature of the insulating gas SF6. For this purpose it possesses a piezoresistive pressure sensor and an evaluation unit with microprocessor. The measured values can be transmitted to a PC or the customer’s own diagnostic system.

Transmitter for monitoring the gas density and dew point in SF6 gas-insulated high-voltage systems; The GD-DP continuously monitors both the density and temperature of the insulating gas SF6 and the dew point. For this purpose it possesses a piezoresistive pressure sensor, a polymer dew point sensor, and an evaluation unit with microprocessor. The measured values can be transmitted to a PC or a customer-specific diagnostic system. The product development was financially supported by the Ministry for Economic Affairs and Energy of the state of Brandenburg.