Net Safety SC310 Catalytic Bead Combustible Gas Sensor for Millennium II Transmitters, Emerson LEL Gas Sensor for Hydrogen, Methane and Propane

What is the Net Safety SC310 catalytic bead combustible gas sensor?

The Net Safety SC310 is Emerson’s catalytic bead sensor for combustible gas detection in % LEL (0-100 % LEL) within the Millennium II series. Its response is non-selective: it reacts to hydrocarbon and non-hydrocarbon flammable gases, from methane and propane to hydrogen, and sends the reading digitally to a Net Safety Millennium II transmitter. Emerson makes a full set of correction factors available to support accurate calibration.

The housing is designed to resist shock and vibration, and Emerson states the sensor shows negligible zero drift from pressure, humidity and temperature changes.

Maintenance note: SensorGuard is the SC310’s protection against high concentrations: when concentrated gas stays in the area, the microprocessor prevents oversaturation (> 100 % LEL) so the sensor does not burn out early, which Emerson says greatly extends sensor life. Emerson ties the full five-year sensor warranty to this protection. Zero drift is specified at ±2 % per month.

What are the Net Safety SC310 specifications?

As printed in the Emerson SC310 data sheet:

Part number	SC310(A/S)-100-ASSY
Detection technology	Catalytic bead, combustible gases [% LEL]
Detection range	0-100 % LEL
Gases detected (partial list)	Methane, Propane, n-Butane, Isobutylene, Hydrogen, Ethane, Pentane, Hexane, Heptane, Ethylene, Propylene
Response time	T50 ≤ 5.5 s; T60 ≤ 6 s; T90 ≤ 12 s
Accuracy	±3 % < 50 %; ±5 % > 50 %
Zero drift	±2 % per month
Repeatability	±1 % LEL full scale
Electromagnetic compatibility (EMC)	IEC 61000-4-3
Operating temperature	-40 °F to +167 °F (-40 °C to +75 °C)
Relative humidity	0-95 % RH non condensing
Ingress protection	IP64
Enclosure material	Aluminum (AL6061) or stainless steel (SS316)
Conduit connection	3/4″ NPT
Sensor separation	Up to 2,000 feet/600 meters (18 AWG cabling)
Transmitter required	Millennium II Series (M21, M22)
Warranty	Five years

Selection note: Accuracy is tighter in the lower half of the range: ±3 % below 50 % and ±5 % above 50 %. Repeatability is ±1 % LEL full scale, against ±2 % LEL for the Net Safety SC311 infrared sensor, while the SC311 responds slightly faster (T90 ≤ 11 s against T90 ≤ 12 s).

Where is the Net Safety SC310 used, and when is the SC311 infrared sensor the better fit?

The SC310 is a fixed % LEL sensor for areas where the flammable gas may not be a hydrocarbon, or where several combustible gases can occur, on a Net Safety Millennium II transmitter. Emerson builds it for extreme industrial environments. Compared with the Net Safety SC311 infrared sensor, per the two data sheets:

• Gases detected: SC310 non-selective, hydrocarbon and non-hydrocarbon, with hydrogen, heptane, isobutylene and propylene on its list; SC311 hydrocarbons only, such as methane, propane, iso-pentane and ethylene.
• Poisoning: Emerson states the SC311 is immune to poisoning; the SC310 relies on SensorGuard against high gas concentrations, and the Millennium II transmitter data sheets describe the catalytic bead technology as poison resistant.
• Response time: SC310 T50 ≤ 5.5 s and T90 ≤ 12 s; SC311 T50 ≤ 4.3 s and T90 ≤ 11 s.
• Zero drift: SC310 ±2 % per month; SC311 < 5 % full scale per year.
• Power: Emerson states both sensors have the lowest power consumption available.
• Warranty: five years on both.

Toxic gas or oxygen deficiency on the same transmitter: the Net Safety ST3 XChem electrochemical sensor. More on choosing a detection technology: PE Energy guide to gas detection systems.

Selection note: Choose the SC310 when hydrogen or another non-hydrocarbon combustible is part of the hazard, because hydrogen is on its detected-gas list and not on the SC311’s. The two sensors have identical housing dimensions, the same -40 °C to +75 °C rating and the same Millennium II transmitters (M21, M22), so moving between catalytic bead and infrared keeps the transmitter and the mounting.

Which approvals, outputs and documents apply to the Net Safety SC310?

Approval strings as printed in the SC310 data sheet:

North American	Class I, Division 1, Groups BCD T5; Class I, Zone 1, AEx/Ex d IIB +H2 T5; -40 °C ≤Ta ≤+75 °C
IECEx	Ex d IIB+H2 T5 Gb; IECEx FMG 12.0007X; -40 °C ≤Ta ≤+75 °C
INMETRO	Ex d IIB+H2 T4 Gb IP66/67
EMC	IEC 61000-4-3

The SC310 communicates digitally with its transmitter; the analog, relay, Modbus or HART output comes from the Millennium II transmitter version. Reference document: SC310 product data, document FGD-PDS-SC310-Catalytic-Bead-Combustible-Sensor, dated July 2016. Emerson model page: Net Safety Millennium II SC310 catalytic bead combustible gas sensor.

Installation note: For dirty or wet locations the SC310 data sheet lists the IPF-001, an IP 66/67 filter for SX3 Series sensors that adds protection against dirt and moisture. The sensor’s own rating is IP64, and its INMETRO marking reads T4 while the North American and IECEx markings read T5.

How do I request a quote for the Net Safety SC310?

Send the part number with the housing, the combustible gas the point must detect (Emerson publishes correction factors for calibration), the Millennium II transmitter, any accessories and the quantity. PE Energy confirms price, availability and lead time with the quote. Request an SC310 quote.

SC310A-100-ASSY	Aluminum housing, combustible gases, 0-100 % LEL
SC310S-100-ASSY	Stainless steel housing, combustible gases, 0-100 % LEL
JB-MPD-A	Termination box, digital output, aluminum
JB-MPD-S	Termination box, digital output, stainless steel
CCS-1	Calibration Cup/Rain Shield/Splash Guard/Dust Filter with DF-1
CC-INLINE	Inline calibration adaptor: brings a slip stream of gas to the sensor and vents it back into the main stream
IPF-001	IP 66/67 filter for SX3 Series sensors, extra protection against dirt and moisture

Model code example: SC310S-100-ASSY = Net Safety SC310 catalytic bead combustible gas sensor, stainless steel housing, combustible gases 0-100 % LEL. The aluminum version is SC310A-100-ASSY (part number pattern SC310(A/S)-100-ASSY).