The proper working of an active safety system depends to a great extent on good detection. For this, not only the type of detector is important, but also its location. A bad location can cause false alarms and could also keep the detector from functioning as it should.
An optical detector can, for example, get contaminated by product deposits. Deposits can also cause malfunctioning in pressure detectors, especially with products that can cake due to moisture. Establishing the correct location is not always simple and is a job for specialists.
Considerations include processes with CIP, excessive wear…
Optical and pressure detectors
There are two kinds of detectors: optical detectors and pressure detectors. Depending on their application, those two groups can be subdivided further.
| Group |
Detection based on |
Kind of detection | Applications | Protection principle |
| Optical | IR | Spark detection |
FSGV(1), stopping of equipment such |
Mainly preventive |
| IR | Flame detection | FLASH, CB(2), extinguishing systems, FSGV | Curative | |
| UV | Flame detection | FLASH, CB, extinguishing systems (3), fire detection, FSGV |
Curative | |
| Pressure | pstat | Static pressure detection | FLASH, CB, FSGV | Curative |
| dp/dt (ROR) | Detection of pressure increase | FLASH,CB, FSGV | Curative |
A number of these detection forms are often assembled in a single housing for reasons of back-up, better usability, etc.
Examples include UV/IR, IR/pstat/ROR
StuvEx currently has the following detectors in its product range:
- PDS: static pressure detector
- PDP: combined detector Pstat, ROR, IR (flame)
- UV: flame detection
- ISD: spark detection
Mechanical and electronic detectors
The simplest detector is the PDS detector. This is a static pressure detector based on a membrane with a switch. The absence of electronics makes this detector very reliable. Thanks to the large membrane, the detector is relatively insensitive to moderate product impact. This detector is also equipped with a mechanical memory.
All other detectors are electronic units that compare the signal of the sensors with their normal state settings. To avoid false alarms, the signal of the sensor is compared several times with the configured alarm and fault thresholds. If the sensor values are still within the alarm window after several samples, the alarm is triggered. Sample rate, sensitivity, etc. can be configured for the specific detector. Detectors such as the PDP detector are also equipped with a memory(4), so that the triggering conditions can be verified after an alarm has been triggered.
Our detectors are made of the right materials
We always use the right materials for our detectors, so that they can be used in even the most demanding processes such as pharmacy, baby food and food in general. All parts that come in contact with the product are made of stainless steel or food approved plastics (in most cases with FDA approval). No glass is used, not even in the optical detectors.
Our detectors are certified
The detectors are always part of a certified ATEX safety system, but they, of course, also have their own certificate as a component. Consequently, any application must be based on the instructions contained the ATEX certificate, the product specifications and the user manual.
Technical specifications
A StuvEx product specialist is at your disposal for advice and comprehensive documentation.
(1) Fast Shutting Gate Valve
(2) Chemical barrier
(3) Water, CO2, steam…
(4) Even if the detector's power supply fails, the memory will remain intact (up to ± 10 years from production).
Interested?
Contact us: a A StuvEx specialist is at your disposal!