Limit monitors to ensure rapid response to gas leak incidents enabling safety to both personnel and assets

LogiDataTech offer state-of-the-art free programmable, self-monitoring limit monitors of to evaluate the measurement signals of connected measuring systems, such as those used for toxic or explosive gases, oxygen, carbon dioxide, and temperature. When exceeding or falling below a specified threshold, they trigger alarms or other downstream functions to alert the measurement system’s operator and enable a quick and efficient response. Thanks to the monitors’ potential-free relay output, it is possible to activate devices, such as: magnetic valves, fans and acoustic transmitters in response to an alarmed incident.

Different sensors can be connected to a limit monitor via 4 - 20 mA interfaces. LogiDataTech offer several connectable measuring systems:  The compact, wall-mounted GWZ-S2.1 and GWZ-S4.1 limit monitors have a plastic housing for wall mounting; they are designed for connection of max. 4 probes on 4 - 20 mA inputs. The GWZ-TS4.1 and GWZ-TS6.1 models have a plastic housing for DIN rail mounting (TS35). They are designed for connection of max. 6 probes on 4 - 20 mA inputs. The freely programmable, self-regulating limit monitors are used for indicating the concentration of gases and vapours. Up to 6 LogiDataTech sensors can be connected to the 4 - 20 mA interface. The sensors are supplied via this device with 24 V DC. There is also a digital input so operators can wire a digital signal contact (e.g. pressure, water level) and a digital input for the external horn reset.

These devices self-monitor the wiring of the sensor. It detects wire break and short circuit while triggering a fault message. The malfunction alarm relay is designed fail-safe, means, in case of failure power supply is cut off (closed-circuit principle) and a power failure can thus be detected.

The limit monitors have 4 potential-free relay outputs. The alarm relay contacts alert the operator when threshold limits are exceeding or fall short of the set threshold limits. For example, they can visually and acoustically trigger pre and main alarm or start-and turn off a fan. The alarm outputs are available with hysteresis, latching or latching prematurely acknowledged. The alarm relay can be assigned a time function (minimum pulse time, maximum pulse time, delayed on/off).

The other relays are a relay to control a horn, a fault alarm relay so operators are aware of cable breaks, short circuits, and electronic failures, while the fault message relay system displays malfunctions. Finally, a test function allows the verification of the output relay.