Hukseflux

Thermal Sensors

SBG04

Water-cooled heat flux sensor – for cone calorimeters
SBG04 is a water-cooled sensor that measures heat flux. SBG04 is mainly used as a calibration reference
standard for testing with cone calorimeters. All specifications and dimensions are standardised for use in cone
calorimeters according to ISO 5660 and ASTM E1354 reaction-to-fire tests. The design includes two watercooling tubes fixed at a 90° angle to the sensor body, with a sensor body of a 0.5 inch diameter. The sensor
may also be used in flammability, fire resistance, and smoke chamber testing. For other water-cooled heat flux
sensors, see the SBG01 and GG01 sensors.

Figure 1 SBG04 water-cooled heat flux sensor.

Introduction
SBG04 measures heat flux in the range of (10 to100) x 103 W/m2. Equipped with a black absorber,heat flux sensors of this type are designed formeasurement in an environment in which heat
flux is dominated by radiation. SBG04’s thermopile
sensor generates an output voltage proportional tothe incoming irradiance. The sensor is watercooled. Water cooling is typically supplied by tap
water connected to the stainless steel in and outlet
tubes. These tubes stand at a 90° angle to the 0.5
inch diameter cylindrical sensor body axis, andparallel to the black sensor surface as required fortesting with cone calorimeters.

Next level technology
SBG04 employs a novel sensor design, which
combines the benefits of foil technology of thetraditional Gardon gauges with those of thethermopile technology of traditional SchmidtBoelter gauges.

SBG04 has several advantages:•cone calorimeter compatible•
all specifications and dimensions
standardised according to ISO 5660 and
ASTM E1354•
reduced diameter of 12.7 mm (0.5 inch)•
reduced installation height•tubes at 90° angle to the axis of body•scratch resistant absorber coating (reducedabsorber height)•safe storage with a practical protection cap.

Suggested use
SBG04 is the sensor of choice as calibrationreference standard for cone calorimeter test
equipment, in accordance to ISO 5660 and ASTM
E1354 reaction-to-fire tests. It is also used inflammability, fire resistance and smoke chamber
tests.

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Measurement uncertainty
The uncertainty of the measurement with SBG04
should be determined case by case. It is afunction of:
1. heat flux sensor properties.
2. uncertainty of calibration and quality
assurance of the local calibration reference
standard.
3. verification of the stability of SBG sensors inday to day measurements, before and afteruse.
4. application-related uncertainties, for example
caused by the unknown contribution ofconvection and the representativeness of themeasurement location.
Hukseflux provides a traceable calibration. The
reference standard at Hukseflux is of secondary
standard level. It has been calibrated bycomparison to the primary standard of the RISE
Research Institutes of Sweden AB.
SBG04 sensors as supplied by Hukseflux arecalibrated according to ISO 14934-3.
Hukseflux is ISO 9001 certified, but not an
accredited measurement laboratory according toISO 17025.

••

NIST (USA), Of the 3 calibration reference
instruments, 2 instruments must be kept
unused until unexpected results appear or
until the first calibration reference standard issent away for recalibration.
to calibrate every 2 years one of the reference
standards against the primary standard. Aftercalibration this instrument is used to verify theuncertainty of the other 2 calibrationreference standards. A single calibrationreference sensor is usually calibrated at
multiple heat flux levels. It can be used as areference in the same heat flux range, and byextrapolation also at higher levels.
to compare working standards to a local
calibration reference standard before every
test and preferably after every test, following
the method specified in ISO 14934- 3. The
comparison requires a local irradiance source,
for example a cone calorimeter.

ISO / ASTM standardised practices
Calibration and use of heat flux sensors (officially“heat flux meters”) such as SBG04 are subject tostandardised practices according to ISO 14934“Reaction-to-Fire tests - calibration of heat fluxmeters” and ISO 5660 “Reaction-to-fire tests —Heat release, smoke production and mass lossrate”. The same procedures will be adopted by
ASTM. In case the user performs accredited
testing or works in an accredited organisation,
the user must comply with these standards.
The ISO 14934 standard has 4 parts:
Part 1: general principle.
Part 2: primary calibration methods.
Part 3: secondary calibration methods.
Part 4: guidance on use of heat flux meters.
The most important requirements of the ISO
14934 standards are:•to have 3 local "secondary standard"calibration reference instruments (i.e. sensors
calibrated using the primary standard
according to ISO14934-2) for calibration ofthe "working standards" (i.e. the instruments
used for day to day work for calibration of testequipment). This may be done at for example

Figure 2 SBG04 is the sensor of choice for cone
calorimeter calibration.

The ISO 5660 standard has 4 parts:
Part 1: Heat release rate (cone calorimeter
method).
Part 3: Guidance on measurement.
Part 4: Measurement of heat release fordetermination of low levels of combustibility.
Part 5: Heat release rate (cone calorimeter
method) and smoke production rate (dynamicmeasurement) under reduced oxygenatmospheres.
The most important requirements of the ISO
5660 standards for SBG04 are:Copyright by Hukseflux. Version 2305. We reserve the right to change specifications without prior notice
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•••

•

•

the flux meter shall be positioned at a locationequivalent to the centre of the specimen faceduring calibration.
the receiving target shall be flat, circular, ofapproximately 12.5 mm (half inch) indiameter with a durable matt black finish.
at maximum intervals of 100 working hours,
check the operating heat flux meter against
the reference heat flux meter.
the calibration of the working heat flux metershall be checked by comparison with two
instruments of the same type and of similar
range held as reference standards and notused for any other purpose. One of thereference standards shall be fully calibrated ata standardizing laboratory at yearly intervals.
the flux meter shall always be used with watercooling.

SBG04 specifications
MeasurandMeasurand in SI units
Sensor technology
Standardisation

Rated measurement
range
Limiting measurement
range
Response time (63 %)Output signal
Output signal range
Spectral range
Full field of view angle
Black coating emissivity
Calibration traceability
Rated cooling watertemperature range
Rated cooling water flow
Calibration laboratory
management system
certification
Accreditation
Calibration method

Standard cable length
Order code standard
versionheat flux
irradiance in W/m2
both Gardon and SchmidtBoelter
all specifications anddimensions standardised foruse in cone calorimeters
according to ISO 5660 andASTM E1354
100 x 103 W/m2
150 x 103 W/m2
< 250 x 10-3 s
DC voltage> 12 x 10-3 V at rated
measurement range
0 to 50 x 10-6 m
180°> 0.95to ITS-90
10 to 30 °C> 10 l/h (0.003 l/s),
preferably 30 l/h (0.01 l/s)
ISO 9001

not accredited
SBGC secondary calibration
method according to ISO
14934-32m
SBG04-100-02

Figure 3 SBG04-100-02 standard model: (1)thermopile sensor with black coating, (2) water coolingtube, outer diameter tubes 3.2 x 10-3 m, (3) sensor
wire tube, (4) tube support ring, positioning stop forcone calorimeter, (5) cable, length 2 m. SBG04 isdelivered with a practical protection cap for safestorage. All dimensions in x 10-3 m.

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SBG04 mounting
To position SBG04 according to the standardpractise of ISO 5660 and ASTM E1354 a “fluxmeter mount” shall be used. The recommendeddimensions for the slot in the mount for SBG04
are provided in figure 4. Contact your cone
calorimeter equipment supplier for an suitable
mount or modification.

Figure 4 Suggested slot dimensions for SBG04 cone
calorimeter “Flux meter mount”.

See also•••

SBG01 water-cooled heat flux sensor with a 1
inch body for measurements < 200 x 103 W/m2.
GG01 Gardon gauge water-cooled high heat flux
sensor for measurements > 250 x 103 W/m2.
HFS01 is a high intensity heat flux sensor
intended for concentrated solar andflammability testing.

About Hukseflux
Hukseflux is the leading expert in measurementof energy transfer. We design and manufacture
sensors and measuring systems that support theenergy transition. We are market leaders in solar
radiation- and heat flux measurement.
Customers are served through the main office in
the Netherlands, and locally owned
representations in the USA, Brazil, India, China,
Southeast Asia and Japan.

Interested in this product?
E-mail us at: info@hukseflux.com

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MARKET LEADER IN HEAT FLUX MEASUREMENT

SBG04 outperforms competing models: how?
SBG04 is the standard heat flux sensor used as calibration reference standard for cone calorimeter test equipment.

Durable flexible cable with strain
relief, rated operating temperature
range up to 200 °C.

World market leader
SBG series is on the market foraround 10 years and used by
the vast majority of fire testing
institutes.

Reduced diameter and height.
All dimensions standardised according to
ISO ISO 5660 and ASTM E1354.
Carbon black absorbing paint,
extremely stable, black surface
slightly retracted to reduce risk ofscratching the sensor surface.

Supplied with protection cap
The added protection cap is a useful tool toprotect the black absorber and guarantees
the sensor lifetime.

Best paperwork
Employed with a variety of sources
Cone calorimeters, IR emitters, fires, flares
etc.

Hukseflux has the paperwork covered; SBG04 isprovided with formally traceable calibration
certificates. We use a secondary calibrationmethod according to ISO 14934-3.

Robust water supply connections at90° angle for cone calorimeter
mounting.
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