OCMA-25 Automatic Oil Content Monitor

Vue d'ensemble

Over the past several decades, HORIBA has designed and manufactured a complete line of high-quality non-dispersing infrared analyzers and analyzer systems. HORIBA has extended infrared gas analyzer technology to the continuous measurement of oil in water for process monitoring and waste water alarm applications. The OCMA oil content analyzers are a unique solution to the problem of continuously and accurately measuring oil content in water; monitoring oil content in boiler water; monitoring process water for hydrocarbon break through; monitoring waste water discharge to meet regulatory requirements. Continuous monitoring meets water pollution control program.


The OCMA-25 meets water pollution control program requirements. A rugged process-type instrument, the OCMA-25 provides a continuous real time measurement of the oil content in a sample stream. The OCMA-25 system is capable of measuring 0 ~ 5, 0 ~ 10, 0 ~ 20, up to 0~100 ppm full scale. The OCMA-25 provides digital display in concentration units, concen-tration alarm functions, and an iso-lated 4 ~ 20 mA DC output signal.

No interference. Based on the principle of solvent extraction and infrared absorptiometry, the OCMA-25 is total-ly insensitive to interferences such as suspended solids, air bubbles, dissolved solids, etc. It is extremely accurate.

  1. Control unit/digital display
  2. Solvent reclaimer
  3. Twin-headed pump
  4. NDIR analyzer
  5. Water separation filter


Sensitive to all oils, the OCMA-25measures oil concentration as thosesubstances which are extracted intofluorochlorocarbon S-316. They are measured at 3.4 microns, which is the major hydrocarbon NDIR absorption band. Both petroleum and vegetable oils may be measured.

Fluorochlorocarbon S-316 solvent reclaimer reduces cost. An activatedcarbon solvent reclaimer is integrated into the OCMA-25 to continuously recover solvent used in the measure-ment. Fluorochlorocarbon S-316 solvent is recycled in the analyzer. This minimizes solvent loss, insuring less maintenance and less cost.

Calibration and cleaning are automatic. The OCMA-25 reduces attended main-tenance time. A built-in automatic calibration function for zero and span can be set to automatically reset and span the analyzer from once each hour to once each 24 hours. During the cali-bration, the sample inlet strainer is cleaned using compressed air supplied by an integral air pump.

Six alarm functions are starndard. The OCMA-25 is completely equipped with visible L.E.D. alarms. These alarms include: oil concentration alarm, out-of-calibration alarms, filter and solvent failure alarms. The oil concentration alarm is fully adjustable from 0 ~ 100% of full-scale. In addition to L.E.D. alarm indication, each alarm condition provides a contact closure rated at 0.5 AMP 110 volts.

Fabriqué par HORIBA



Solvent extraction/non-dispersive infrared absorptiometry


Automatic, continuous measurement


0 ~ 10 or 0 ~ 20 ppm (also available 0 ~ 5 and 0 ~ 100 ppm)


Within ±3% of full scale

Zero drift: 

Within ±5% of full scale per 8 hours (ambient temperature fluctuation within ±5°C)


Within ±2% of full scale

Response time: 

Within 5 minutes (90% response), Within 10 min for the versions having 0 ~ 5 ppm or 0 ~ 100 ppm range


Mode: Automatic
Cycle: 1 to 24 hours, field selectable
Calibration time: 20 minutes
Zero: Using water
Span: By means of equivalent optical signal


Digital, 3 digits in ppm concentration units

Signal output: 

4 ~ 20 mA DC, 0 ~ 1 V DC (simultaneous output) isolated, load resistance: less than 750

Status signal output: 

Contact signal rating: 110 V AC, 0.5 A or 24 V AC, 1 A (resistive load) "Measurement in progress" "Calibration in progress" "Maintenance in progress" "Zero Calibration failure"* "Span Calibration Failure"* "Filter/Solvent failure"* "Greater than full scale value alarm"* "Oil conentration alarm"* "Power failure alarm"* ( j Common maintenance alarm output)

Remote operation signal input: 

"CAL START", "MEAS" Contact signal capacity: 30 V DC, more than 0.1 A

Sample requirements: 

Temperature: 2 ~ 30°C (within ±5°C fluctuation) Flow rate: 4 ~ 20 L/min standard, 0.3 ~ 2 L/min boiler water


More than 10 µS/cm

Suspended solids: 

Less than 30mg/L To be filtered through 150 mesh or finer stainless steel net.
Note: Consult HORIBA for samples including any surfactant.

Environmental condition: 

Ambient temperature: 0 ~ 40°C (in-door installation), Optional weather-proof enclosures and custom system designs.
Humidity: Less than 90%


AC line, max. 950 VA (Models are available for 100, 115, 220, 230 or 240 V AC at 50/60 Hz operation as specified.)


Fluorochlorocarbon S-316 Specific gravity: approx. 1.7 at 25°C
Consumption: approx. 1 kg/month


Munsell 7.5 BG 7/1.5


500(W) x 500(D) x 1500(H)mm, 19.7(W) X 19.7(D) x 59.0(H) in


approx. 150 kg, 330 Ibs