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775 Combination CO & Combustible Gas Monitor


The combo CO/Combustible gas detector is the first of its kind to combine both detection technologies into one easy to use hand-held and affordable instrument.

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The TPI 775 is a state-of-the-art Carbon Monoxide and Combustible Gas Leak Detector. It is the first of its kind to combine both detection technologies into one easy to use hand-held affordable instrument. The 775 combines the features of both the  770 and 720b.

  • One hand operation
  • 40.64cm Flexible Gooseneck
  • Auto Zero
  • Backlight
  • Visible and audible alarm

Standard Accessories
• Instruction Manual
• Soft Pouch

Optional Accessories
• Earphones


Model 775 Applications

  • CO safety measurements in and around combustion sources
  • Ambient CO safety checks
  • Combustible Gas Detection

Tech Tips

Don’t expose yourself to Carbon Monoxide!

Review the list below for the maximum allowable exposure limits and symptoms developed with CO inhalation.

  • 9ppm: The maximum allowable concentration for short term exposure in a living area according to ASHRAE
  • 50ppm: The Federal OSHA standard for continuous exposure in any eight hour period.
  • 200ppm*: Maximum concentration allowable any time according to OSHA. Slight headaches, fatigue, dizziness, nausea after 2-3 hours.
  • 400ppm*: Frontal headaches within 1-2 hours, life threatening after 3 hours. Maximum allowable limit in flue gas according to EPA and AGA.
  • 800ppm*: Headache, dizziness, nausea, and convulsions with 45 minutes. Unconsciousness within 2 hours. Death within 2-3 minutes.
  • 1600ppm*: Headache, dizziness, and nausea within 20 minutes. Death within 1 hour.
  • 3200ppm*: Headache, dizziness, and nausea within 5-10 minutes. Death within 30 minutes.
  • 6400ppm*: Headache, dizziness, and nausea within 1-2 minutes. Death within 10-15 minutes.
  • 12800ppm*: Death within 1-3 minutes.

* With exposure to this concentration and higher the effects can vary depending on size, age, sex, and health.


Product Documentationpdf-icon1

Click below to view or download product documentation PDFs:

775 Manual

775 Product Sheet


IR Printer Port No

 Model 775 Specifications
 Carbon Monoxide (CO) Measurement Range 0 ~ 2,000ppm
 Accuracy ±5ppm or 5% of reading whichever is greater
 Resolution 1ppm
 Data Storage No
 Flue Probe No
 Internal Pump No
 Combustible Gas Leak Detection Yes
 Backlight Yes
 Alarm Audible + Visual
 Power Supply 1.5V AA (2)
 Dimensions 9.5” x 2.9” x 2.2” (240 x 74 x 55 mm)
 Weight 1.05lbs (476g)
 Warranty 3-year limited warranty 2-year sensor warranty


Frequently Asked Questions

Why should I purchase a pump driven CO analyzer rather than a less expensive CO monitor?
A pump driven analyzer is a much more versatile tool. The pump draws a sample into the instrument which allows source pinpointing. A pump driven instrumentwill also respond faster, and can be used for hot air (flue) sampling.

Can a CO analyzer be used for heat exchanger testing?
While a CO analyzer can provide a safety test of the furnace, it cannot provide a discernable test for heat exchanger integrity. The TPI HXG2 and HETKIT are recommended for this test and together are AGA approved.

How often should I calibrate my CO analyzer?
It depends on the use of the instrument. If used for service work, it is recommended that an annual calibration be performed. If any aspect of worker safety is included in the instrument’s job, monthly calibration is recommended.

If I perform my own calibration, do I increase my liability?
As long as traceable calibration gas is used and manufacturer’s calibration procedures are followed, liability will be minimized. Calibration records should be documented and retained.

How many calibrations can I expect out of a 21 liter bottle of calibration gas?
35-50 calibrations

How long will the CO sensor last?
Two to three years.

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