AP Sensing: Fiber-optic Linear Heat Detector N45 LHD series – GSA25 Finalist Shortlist Highlight
The new N45 LHD series of fiber-optic Linear Heat Detectors (FO-LHD) can achieve a measuring range of up to 16km per channel with up to 4 independent sensor channels. Each measuring channel can be divided into up to 2000 zones with up to 5 individual alarm criteria per zone. Commissioning via standard web browser has been significantly simplified by assistance programs.
The N45 LHD series communicates via various network protocols; furthermore, up to 98 output relays can be integrated. The Ø4mm sensor cables have two independent fiber optic fibers that enable fully redundant monitoring of customers assets. Due to the large number of approvals (EN (VdS), FM, UL, SIL2, EX), the new N45 LHD series is already valued in many projects globally.
With the new N45 LHD series, the measurement ranges have been extended from 10 to 16km per channel with a significant reduction in measurement times from 10 to 5 seconds and less. This makes the new N45 LHD series the most powerful system in the Linear Heat Detector market and can therefore also be used for very long-range monitoring in very long tunnel systems and storage facilities, e.g. floating roof tank farms.
For targeted information and alarming, the sensor cables can be segmented into up to 2,000 zones per channel. Each zone can be assigned its own parameter set with 5 alarm parameters. Zones can be adjacent to another, overlap completely or partially. Areas without zones or alarm parameters can also be added along the sensor cable; a temperature increase in this section then does not lead to a reaction of the fiber optic LHD. These zones without alarm parameters are used, for example, between two floating roof tanks in which the sensor cable is routed through a protective tube.
Another innovation is the evaluation of the measured data. The measured data for the static alarm parameters with Trace A and the dynamic gradient alarm parameters with Trace B are calculated using the two evaluation methods (Traces A and B). The static alarm criteria are the maximum temperature criterion and the zone difference criterion; the dynamic alarm criteria are three temperature gradients that evaluate the increase in temperature over time; a total of 5 alarm criteria per zone. With Trace A/B, two simultaneous measurements can be configured on one device, for even more flexible and precise measurement configuration in the project.
In terms of user-friendliness, the N45 LHD can be put into operation using a standard web browser; additional software is not necessary. During commissioning, user-friendly assistance programs (wizards, auto/quick setup, drag & drop calibration) provide support in setting standardized alarm parameters in accordance with EN54-22 and UL521.
