705 HT Series of Flammable Gas Sensors
Explosion-Proof Transmitters

UL certified, explosion-proof flammable gas detectors with high temperature version certified to 150°C.
Features & Benefits
Fast response speed/low power consumption
Greater than 5 year operating life
High-grade aluminum construction 
Quick Specs
 Operating temperature range: -25° to +150°C (-13°F to +302°F)
 Operating pressure: 75 to 110kPa (750 to 1100mbar)

 Range: 0-20% LEL, 0-100% LEL (control card dependent)

Product Overview

The Model 705 high temperature sensor has been specifically designed for the detection of combustible gases in high temperature hazardous area locations.  Typical applications include turbine enclosures and drying ovens used in solvent based printing and coating machines.

These applications require a sensor that provides reliable and stable detection allowing low-level alarm settings across a wide temperature range. Utilizing a specially matched pair of Sieger poison resistant combustible gas detection elements, the Model 705 High Temperature Sensor has a very stable baseline allowing alarm trip points to be set as low as 5% LEL across a temperature range of -25°C to +150°C (-3°F to +302°F). The gas measuring range can be configured from 0-20% LEL up to 0-100% LEL depending on the type of controller used. 

The detector elements are housed in a UL hazardous area approved explosion proof assembly, and provide an industry standard 3 wire mV bridge output which can be connected to a suitable control device or converted to an analog output signal via a field transmitter.

Additional Features and Benefits:
Excellent Performance
•  Certified for hazardous location operation  up to +150°C (+302°F)
•  Alarm trip points as low as 5% LEL
•  Fast speed of response
•  Poison resistant detectors
•  Low power consumption
Cost Effective

•  Low cost disposable sensor
•  Greater than 5 year typical operating life

Reliable Operation
•  Specially matched ‘Sieger’ detectors provide highest stability
•  Proven technology from the World leader in combustible gas detection

Flexibility
•  Measuring ranges from 0-20% LEL to 0-100% LEL
•  Wide range of accessories

Robust Construction
•  UL approved explosion proof enclosure
•  High grade Aluminum construction.

High temperature sensor
for combustible gases

The Model 705 high temperature sensor has
been specifically designed for the detection
of combustible gases in high temperature
hazardous area locations.
Typical applications include turbine
enclosures and drying ovens used in
solvent based printing and coating machines.

Excellent Performance
• Certified for hazardous location operation
up to +150°C (+302°F)
• Alarm trip points as low as 5% LEL
• Fast speed of response
• Poison resistant detectors
• Low power consumption
Cost Effective
• Low cost disposable sensor
• Greater than 5 year typical operating life
Reliable Operation
• Specially matched ‘Sieger’ detectors provide
highest stability
• Proven technology from the World leader
in combustible gas detection
Flexibility
• Measuring ranges from 0-20% LEL
to 0-100% LEL
• Wide range of accessories
Robust Construction
• UL approved explosion proof enclosure
• High grade Aluminum construction
These applications require a sensor that provides
reliable and stable detection allowing low level
alarm settings across a wide temperature range.
Utilizing a specially matched pair of Sieger poison
resistant combustible gas detection elements, the
Model 705 High Temperature Sensor has a very
stable baseline allowing alarm trip points to be set
as low as 5% LEL across a temperature range
of -25°C to +150°C (-3°F to +302°F). The gas
measuring range can be configured from 0-20%
LEL up to 0-100% LEL depending on the type of
controller used.
The detector elements are housed in a UL
hazardous area approved explosion proof
assembly, and provide an industry standard 3 wire
mV bridge output which can be connected to a
suitable control device or converted to an analog
output signal via a field transmitter. 

General Specification

Range 0-20% LEL, 0-100% LEL (Control card dependent)
Speed of Response2 T60 Less than 6 seconds.
T90 Less than 10 seconds.
Minimum Alarm Level3 5% LEL
Output Signal mV bridge
Operating Temperature -25°C to +150°C (-13°F to +302°F)
Operating Humidity Continuous: 20 to 90% RH
Intermittent: 10 to 99% RH
Operating Pressure 75 to 110kPa (750 to 1100mbar)
Stability (zero) With time: Less than ±5% LEL/year
With temperature: Less than ±3% LEL
With humidity: Less than ±3% LEL
With pressure: Less than ±3% LEL
Stability (span) With time: Less than ±5% LEL/year
With temperature: Less than ±4% LEL
With humidity: Less than ±3% LEL
With pressure: Less than ±3% LEL
Linearity Better than ±5% fsd
Repeatability Better than ±2% LEL
Warm-up Time 30 minutes
Detector Operating Life4 More than 5 years (typical)
Storage Life Typically, no degredation has been observed in clean, stable conditions for up to 5 years
Power Consumption 0.7W at 200mA
Enclosure Material Aluminum
Mounting Thread 3⁄4“ NPT
Weight 200g (7oz)
Certification UL Hazardous location approval
Class1, Div1, groups B, C and D Tamb: -25°C to +150°C
Notes:
1. Typical performance figures for a sensor calibrated on 10% LEL methane and tested at 20°C and 50% RH.
2. T60/T90 defined as the time to achieve 60% and 90% of the signal obtained after 5 minutes exposure to 50% FSD gas concentration.
3. With recommended 3 month calibration period.
4. In clean atmosphere.

Our Product Range

Fixed Gas Monitoring
Honeywell Analytics offers a wide range
of fixed gas detection solutions for a
diverse array of industries and applications
including: Commercial properties, industrial
applications, semiconductor manufacturers,
energy plants and petrochemical sites.
Portable Gas Monitoring
When it comes to personal protection from
gas hazards, Honeywell Analytics has a wide
range of reliable solutions ideally suited for
use in confined or enclosed spaces.
These include:
Detection of flammable, oxygen and
toxic gases
Single gas personal monitors – worn by
the individual
Multi-gas portable gas monitors – used
for confined space entry and regulatory
compliance
Multi-gas transportable monitors – used
for temporary protection of area
during site construction and
maintenance activities
Technical Services
At Honeywell Analytics, we believe in the
value of great service and customer care.
Our key commitment is providing complete
and total customer satisfaction. Here are just
a few of the services we can offer:
Full technical support
Expert team on hand to answer
questions and queries
Fully equipped workshops to ensure
quick turnaround on repairs
Comprehensive service engineer network
Training on product use and maintenance
Mobile calibration service
Customised programmes of
preventative/corrective maintenance
Extended warranties on products