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Model 270SF Heated Sample Probe

Model 270SF Extractive Gas Sampling Probe
The Universal Analyzers Model 270 (Div II & Zone II Certified) heated sample probe is designed for continuous use in extractive gas sampling systems to be installed in an Electrically Classified Hazardous Area. Common uses are refineries, petrochemical and chemical locations. The modular design is used to filter dust and particulate from a wide variety of gas streams in exhaust stacks and duct applications. The sample probe is designed with the end user in mind and comes with a unique no-tools design for filter replacement. This versatile probe is available in a number of configurations with many options to customize it to specific applications.

Available Options:

  • Choice of Flange Size: ANSI & DN
  • Choice of probe tube lengths and materials
  • Filter chamber blow back with integrated solenoid valve
  • Calibration gas inlet connection with check valve
  • Fiberglass or Stainless Steel Weather Enclosures NEMA 4X-IP65
  • FM Approval for NEC Class I, Div. II groups a,b,c,d
  • CSA Approval for NEC Class I, Div II Groups a,b,c,d
  • TÜV Approval for ATEX Ex II 3 G Ex nA IIC 175°C (T3)


To avoid condensation, a self regulating heater is used to keep the filter Chamber and tubing connections hot and above the sample dew-point. Temperature is controlled up to 340°F (171°C) and includes a low temperature contact alarm output. The standard filter element is constructed of a non-corrosive 2µm Ceramic material with Viton seals as standard. For continuous, low maintenance operation, it is recommended to provide blow back for periodic cleaning of the filter chamber and probe tube. High-Pressure plant air is stored in an on-board accumulator vessel and then released through an integrated high-flow solenoid valve. Easy access to the probe tube is allowed through the design of a sub-flange that allows removal of the filter chamber/probe tube while leaving the enclosure attached to the stack/duct. For ease of installation, the model 270 comes complete with a sample line heat shrink boot and all electrical connections are within the enclosure eliminating break out wiring to external electrical junction enclosures.


  • Easy “no tool” filter element replacement
  • Sub flange for easy filter chamber/probe tube removal
  • Efficient blow back
  • Fiberglass or Stainless Steel environmental protection (NEMA 4X-IP65)
  • Cartridge Heaters
  • Self-Limiting temperature control
  • Heated filter chamber with insulation wrap
  • Rugged construction
  • Corrosion resistant wetted parts
  • All electrical and pneumatic connections within enclosure

Technical Specifications

Sample Flow Rate:  0 to 20 LPM
Calibration Gas Flow Requirement:  Sample flow rate plus 10%
Operating Pressure Drop at 10 LPM:  12” water column
Maximum Stack Gas Temperature:  700°F (370°C)

Filter Chamber Temperature: 

340°F (171°C)

Enclosure Dimensions H x W x D:
     Stainless Steel:


18” x 16” x 10” (458mm x 407mm x 255mm)

16” x 14” x 18” (407mm x 356mm x 203mm HWD

Weight:  25 LB (12 KG) (Plus Probe)

Input Power Requirement: 

150 WATTS / 350 WATTS with optional heated enclosure*
Input Voltage Requirement: 115 or 230 VAC at 50/60 HZ (External Fuse Required of 20A or Less)
Electrical Classification: FM/CSA Class I, Div 2, Groups A, B, C, & D & ATEX II 3G Ex nA IIC 175oC (T3)

Temperature Classification: 

FM/CSA T3A, ATEX 175oC (T3)
Ambient Temperature Operating: 200°F (Maximum 93°C)
Blowback Tank Volume: 0.7 SCF (19.8L) when at 100PSIG (7.4Barg) 
Blowback Duration: 0.5 Secs to empty accumulator 
Blowback Timer Period:
External control (without timer card)

15 minutes to 24 hours (with timer card), located in unclassified area

NEMA 4X/IP65 Fiberglass (Standard)

NEMA 4X/IP65 Stainless Steel (Optional)

 Sample Line Connection:

3” Heat Shrink Boot (Standard)

4” Heat Shrink Boot (Optional)

2” Heat Shrink Boot (Optional)

Heater Type:  Rod Heaters in Aluminum Block controlled with thermal switch
Available Filter Chamber Materials:

316 Stainless Steel (Standard)

316 SS, SilcoNert™ Coated (Optional)

Hastelloy C-276 (Optional)

Available Filter Element Types:

2 µm Ceramic (Standard)

0.1 µm Ceramic (Optional)

0.1 µm Glass-Fiber (Optional)

2 µm 316 Stainless Steel (Optional)

*ATEX only