H2 measuring device for connection with sensors H2-CNI 0-10V-I and H2-meTCD 0-10V (option: H2-CNI 4-20mA-I and H2-meTCD 4-20mA). With 2.4“ TFT color display to monitor measuring data (H2 volume fraction and transient) and data logger for registering data (configurable). The device has a connector to control a three-colored 24V LED warning light (green, yellow = pre-alarm for > 2 vol-% H2, red = main alarm for > 4 vol-%), switched by relays. The device consists of anodized aluminium profiles (Al Mg Si 0.5) with light grey capps on the side (polyamide 6.6 FR). Size = 140 mm x 105 mm x 70 mm. Assembly on a top-hat rail according to DIN EN 60715 TH 35. Voltage connector 24 V with 5.5x2.5 mm clinch socket. Sensor connector with 4 pole-round connector. Optical control of the heating current of the H2-CNI 0-10V-I sensor with LED. Alarm connector with 4 pole circular connector (90 degree, IP 40). Connection to data logger with micro-USB 2.0 metal socket. All connectors at front side. With illuminated on-off switch.