New Ceramic Catalytic Method
Sensor: NC

Stationary sensor
Example: NCF-6319

Stationary sensor
Example: NC-6239

1. Brief description

This sensor uses a ultra-atomized oxidant catalyst (a new ceramic) to detect gas in awide range of concentrations from a low level (ppm) to the lower-explosion-limit (LEL).
It is an epoch-making sensor independently developed by us as a sensor designed
specifically for combustible gas.

Portable sensor
Example: NCR-6309

Category

Detectable gas

SolidCombustible

2. Structure and principles[Structure]

A new ceramic-based sensor consists of a detector element and acompensation element (some models include no compensationelement). The detector element consists of a coil of a precious-metalwire and a ultra-atomized oxidant catalyst (a new ceramic)—a catalyst
active against combustible gas—sintered on the coil along with analumina support. The element burns in reaction to any detectable gas.
The compensation element consists of a coil of a precious-metal wireand glass—a substance inactive against combustible gas—sintered on
the coil along with an alumina support. This element corrects the effectof the atmosphere.

[Principles]

The precious-metal wire coil heats the detector element to 300℃ to450℃. Then, a combustible gas burns on the surface of the detector
element, increasing the temperature of the element. With changes intemperature, the precious-metal wire coil, a component of the element,changes in resistance. The resistance changes almost in proportion to
the concentration of the gas. The bridge circuit allows the sensor torecognize the change in resistance as the voltage to determine theconcentration of the gas.

[Conceptual rendering of the sensor elements]

Oxidation catalyst +alumina support

Precious-metal
wire coil

Glass +
alumina support

Precious-metal
wire coil

0.5-1.4 mm

0.5-1.4 mm

0.8-1.4 mm
Compensation element

0.8-1.4 mm
Detector element[Bridge circuit]Decrease element temperature=> Decreased resistance

Increased element temperature=> Increased resistanceCompensationelement＋

Detector element－Sensor output

VSideresistance R

Sensor voltage Vs

3. Features(of the sensor NC-6239 as an example)○ Output characteristics

The catalyst used in the detector
element provides improved
combustion reactivity. Thisefficiently produces combustion
heat, allowing the sensor to detect
lower concentrations (ppm) ofgases undetectable by catalytic
combustion-based sensors.

○ ResponsivenessThe combustion heat produced on
the surface of the detector elementtransfers to the precious-metal wirecoil, changes the resistance of thebridge circuit, and then transforms
into signals. With a high reaction
rate, this sensor excels in
responsiveness, accuracy, andreproducibility.

○Temperature andhumidity characteristics

100Outputratio(%)
00CH4100

Gas concentration(ppm)

2000

Gas OutCombustible
gases in general
Combustible
gases in general
MethaneCombustible
gases in general
MethaneVinyl chloride

CH49005000
The materials used in theelements have high electricalresistances and less likely to Reading(ppm)
be affected by thetemperature and humidity in0
the use environment,-20
allowing the reading to stayalmost constant.

Temp char
Hum charTemperature(℃)

60○ Detectable concentrations

Outputratio(%)

The sensor detects a wide range of concentrations fromlow levels (ppm) to high levels (% LEL).
0Gas In0Time (sec.)

100

4. Detectable gas, molecular formula, model, and detection
range (examples)
Detectable gas

Humidity (% RH) (40℃ atmosphere)

Molecularformula

Model #Detection
range

-

NCR-6309

0-100%LEL-

NCF-6319

0-100%LEL

CH4

NCF-6318

0-100%LEL-NC-6211

CH4NC-6239

C2H3Cl

NC-6214ppm level to
100% LEL

5. Products of this type (examples)○Stationary products... SD-3NC, SD-3DNC,
GD-A80, GD-A80D, SD-1 (TYPE NC),
SD-D58･DC (TYPE NC)○Portable products... GX-3R, GX-3R Pro, GP-03,
GX-2012, GX-8000GX-3R Pro