DEGA NSII LCD
Gas Detector
Conductor
types: catalytic, electrochemical, infrared, (PID), semiconductor
Signalling
Sound and optical signaling & Explosive environment certification
Relays
Output 4-20 mA, RS485 (Modbus), 4 x relays
Detection of
Toxic and explosive gases including oxygen
Basic gas detection methods:
CL – catalytic sensor (Pelistor)
They work on the principle of catalytic combustion – the gas concentration is measured based on the amount of heat released during the controlled combustion reaction. The reaction is supported by a suitable temperature and the presence of a catalyst. These sensors can be used to detect a wide range of flammable gases. The sensors are characterized by a fast response. They require at least 10% oxygen in the air for their proper function.
EL – electrochemical sensor
They work on the principle of changing the electrical parameters of the electrodes placed in the electrolyte as a result of the oxidation or reduction reaction of the detected gas on their surface. These sensors show good selectivity and ability to detect very low concentrations of toxic gases.
IL – infrared sensor
The highest quality sensing method. They work on the principle of infrared spectroscopy. The sensors have excellent selectivity for organic substances, do not need any oxygen content in the atmosphere for their operation and are resistant to catalytic poisons (sulphur and silicon compounds) that cause a change in the sensitivity of catalytic sensors. They are also characterized by great stability and a long service life.
SL – semiconductor sensor
They work on the principle of changing the electrical conductivity of the semiconductor when the concentration of the detected gas changes. The advantage is their long service life when working in a clean environment and a wide range for various types of gases and vapors. The disadvantage is low selectivity – the sensor reacts to a large extent even to gases for which it is not calibrated.
PID – photoionization sensor
A sensitive sensing method to detect a wide range of VOCs – volatile organic substances. The sensor non-selectively detects all VOCs in the air already at concentrations in ppm units.
| Power voltage | 8 – 30 VDC |
| Exit | 4-20 mA, RS485, Modbus, Piezo buzzer |
| Degree of protection by the cover | IP 54, with DEGA WATER CAP IP 66 cover |
| Power consumption | 1.2W |
| Dimensions | 140 x 140 x 70 mm (WxHxD) |
| Mass | 0.8 kg |
| Sensor type | catalytic, electrochemical, infrared, photoionization, semiconductor |
| Estimated sensor lifetime in the sensor in a clean environment | catalytic/semiconductor (1-2 years), electrochemical (1-3 years), infrared (5 years and more), photoionization (5000 hours) |
| Relative humidity of the surrounding air | 0-95% RH |
| Location | BE3N2 – potentially explosive atmosphere, zone 2 |
The DEGA NS II LCD detector is part of the gas detection system and is placed in the monitored area where a critical situation can arise due to the accumulation of flammable or toxic substances, even in an explosive environment. The detector converts the measured substance concentration into a unified 4-20 mA current signal. The detector is equipped with an LCD display for displaying the current measured concentration of the detected substance and a quad relay.
The detector can be connected to the evaluation centers DEGA UPA III, DEGA UKA III and DEGA UDA III via RS485.
Modules:
- DEGA NS II LCD RS485 (internal RS485 output)
- DEGA NS II LCD Relay module (internal 4 relays, 250 V/10 A)
- DEGA NS II LCD Buzzer (internal buzzer on PCB, 4 VDC, 7 VDC, 30 mA, 88 dB)
Accessories:
- DEGA NS II LCD mechanical cover
- DEGA NS II LCD stainless cover
- DEGA WATER CAP
- DEGA FUNNEL
- DEGA GAS INLET (calibration attachment)
- DEGA NS II SU (replacement sensor unit)