APHA-370 Ambient THC monitor


The APHA-370 continuously monitors atmospheric THC, NMHC, and CH4 concentrations using a cross-flow modulated selective combustion type method combined with a hydrogen ion detection method. The APHA-370 employs an independent, internal dry-method sampling device to achieve the highest levels of sensitivity and accuracy.

AP-370 Series product literature


The APHA-370 uses a combination of the flame ionization detection method and selective-combustion.
This gives it the advantage of the single-detector method plus the ability to perform continuous measurements, free of zero-drift, for THC, NMHC, and CH4. The design gives great stability and high sensitivity (0-5 ppm F.S.)

The APHA-370 has a relative-sensitivity correction function for CH4 and NMHC.

All the necessary features are built right into a single rack-sized instrument, including a catalytic unit for selective combustion (i.e., an NMHC cutter); a cataytic unit for generating reference gas and auxiliary combustion air (standard); and a sampling pump. The only supplemental gas required is H2.

Manufactured by HORIBA



Flame ionization detection (FID) with selective combustion


THC, NMHC, and CH4 in ambient air


Standard ranges: 0-5/10/20/50 ppmC*; auto range ~ manual range selectable; can be operated by remote switching.
Optional (measurable) ranges: 4 ranges selectable from 0-100 ppmC, 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. 0.9 L/min


Measured value, range, alarm, maintenance screen


During AIC, zero calibration error, span calibration error, temperature error in zero gas purifier, ignition failure error, 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. 33 kg.

*ppmC is shown as symbol, not as unit.


AP-370 series Air Pollution Monitor Brochure uploaded on 2013/12/20 (PDF:1.2MB)