APMA-370 Ambient Carbon Monoxide Monitor


The APMA-370 is a device for continuously monitoring CO concentrations using a Non-dispersion cross modulation infrared analysis method. The APMA-370 employs an independent, internal dry-method sampling device to achieve the highest levels of sensitivity and accuracy. The dry method, due to its capability for continuously monitoring and instantaneously analyzing of gas in its unaltered state as well as its minimal maintenance requirements, has been a preferred method for monitoring the atmospheric pollution.

AP-370 Series product literature


The cross flow modulation type, infrared-absorption technology eliminates the need for adjusting optical alignment. For the user, this means very stable and sensitive (5 ppm F.S.) measurements.

The APMA-370 uses an AS type (antishock) interference-compensating detector, and a purified reference gas. The reference gas is generated by purging the sample through an oxidation process, where an oxidizing catalyst burns the CO to CO2. These features eliminate interference from other elements, resulting in highly accurate measurements.

The APMA-370 does not use such components as reflecting mirrors, that attract foreign matter. This means the optical bench stays clean assuring you of stable results over long periods of time.


  • Approval according to EN 14626: TÜV 936/21204643/B
  • Continuous measurement of CO in ambient air
  • "Cross Flow" Modulation principle for stable measurements
  • interference-compensating detector to suppress the influences of moisture
  • Critical orifice for constant flow
  • Pressure and temperature compensated
  • Optimized components to reduce maintenance costs and power consumption
  • Reduced weight design allows easier handling
  • Internal sample gas pump
  • Optional module for internal control function
  • Large LCD touch-screen display (117 x 88 mm)
  • Password protection against unauthorized access
  • Remote software for an external operation
  • High connectivity via RS232, Ethernet or analog (optional)
  • Internal memory for different average values, calibration history and alarm history
  • CF slot allows for memory expansion

Manufactured by HORIBA



Cross flow modulation, non-dispersive infrared (NDIR) absorption technology


CO in ambient air


Standard ranges: 0-10/20/50/100 ppm; 0-5/10/20/50 ppm; auto range ~ manual range selectable; can be operated by remote switching.
Optional (measurable) ranges: 4 ranges selectable from 0-200 ppm, within 10 times range ratio; auto range ~ manual range selectable; can be operated by remote switching.


±1.0% of F.S.


±1.0% of F.S.

Sample gas flow rate

Approx. 1.5L/min


Measured value, range, alarm, maintenance screen


During AIC, zero calibration error, span calibration error, temperature error in catalyzer, etc.

On-screen messages are available in four languages

English, German, French, and Japanese.


• 0-1 V/0-10 V/4-20 mA, to be specified (2 systems: either (1) momentary value and integrated or (2) moving average value) 
• Contact input/output 
• RS-232C


100/110/115/120/220/230/240 VAC, 50/60 Hz (to be specified)


430(W) x 550(D) x 221(H) mm


Approx. 16 kg.

** Certified to U.S. EPA Reference Method RFCA