Sierra Instruments 840-L-4-V1 Mass Flow Controller

SideTrak 840-L Mass Flow Controller, model 840-L-4-V1, from Sierra Instruments is an analog mass flow controller built on Sierra's thermal mass flow sensing platform. It is designed for precise, low-flow gas control across laboratory, analytical, and industrial settings, delivering repeatable gas flow for a broad range of gases; Sierra emphasizes compatibility with nearly every gas in its flow portfolio. The 840-L designation identifies the low-flow variant within the SideTrak 840 family, enabling tight control at the low end of the flow spectrum. The SideTrak 840 line is modular and scalable—up to eight MFCs can be connected on a single manifold—facilitating compact, multi-channel gas delivery systems. This MFC is built for demanding environments and sits within Sierra's broader flow-instrument ecosystem used in semiconductor (and other tech) processing, biotech, chemical processing, analytical instrumentation, and research applications. The 840 family is known for long-term stability and low drift within a rugged thermal mass flow technology framework, providing accurate gas metering essential for calibration, precise delivery, and process control.