Original front panel providing enhanced visibility and operation Restorable sensor coefficient data with new memory back-up function.

Previously MEXA-700λII used know-how and ingenuity gathered from HORIBA air-to-fuel ratio measurement technologies used worldwide, to provide the highest level of performance.
The MEXA-730λ adopts this performance and adds original design for enhanced visibility and operation.
A new sensor coefficient data memory function makes it possible to restore back-up data, providing faster start-up times and saving valuable operation time.

This enhanced device will meet your multiple testing requirements covering applications from, lab analysis of air-to-fuel ratio, excess air ratio and oxygen concentration, to on-board real time measurement.

Front Panel


Typical display screens

Easy-to-see display with improved black backgroundTypical display screens


  • Engine research and development
  • Engine tuning
  • Catalyst development
  • Exhaust gas adjustment
  • On-board evaluation
  • ECU adjustment

Meets your need to measure air-to-fuel ratio under various applications

Provides stability with air-to-fuel analyzing sensor
100% inspection of sensor guarantees accuracyTo meet the stringent measurement conditions of research and development, the on-board auto sensor is produced specifically for air-to-fuel evaluation.  Each unit undergoes thorough inspection to guarantee accuracy. As a standard unit for air-to-fuel ratio measurement, the MEXA-730λ provides reliable accurate performance.
Sensors of MEXA-700λ/700λII can be used with MEXA-730λ.

Wide measurement range applicable to lean-burn engine development
The MEXA-730λ can handle various applications with its wide measurement range. Use it in the front line of development for sure evaluation of any type of engine you are working on,including lean-burn.

Versatility inherited from MEXA-700λ
The MEXA-730λ can be mounted on vehicle dashboards, table-tops, or in a 19-inch rack cabinet. It is easily transported from location to location providing the versatile characteristics required for your testing requirements.

Can be stacked for multi-channel measurement
Multi-channel measurements are easily accommodated by using several MEXA-730λ units simultaneously, for example, to monitor air-to-fuel ratio in each cylinder.  The stable and compact design of the MEXA-730λ permits the instruments to be safely stacked for maximum convenience.

Small DC drive allows on-board mounting for convenient operation from the dashboard or complementary locations.


Calibration unit (Bubbler)
Calibration unit (Bubbler)

Hergestellt von HORIBA


Control unit

Model name


Display range

A/F : 3.99 to 500.0
λ : 0.275 to 30.00
O2 : 0.00 to 99.99 vol%

Accuracy of A/F

(Guarantee range is from 9.5 to 200 A/F)
(Model gas at room temperature, atmospheric pressure is used):
With 3-point calibration at 9.5 A/F, stoichiometric point and 60.0 A/F
9.50 A/F to stoichiometric point: within ±0.3 A/F
at stoichiometric point: within ±0.1 A/F
stoichiometric point to 20.00 A/F: within ±0.3 A/F
20.01 to 30.00 A/F: within ±0.7 A/F
30.01 to 40.00 A/F: within ±1.0 A/F
40.01 to 50.00 A/F: within ±1.5 A/F
50.01 to 60.00 A/F: within ±2.0 A/F
60.01 to 80.00 A/F: within ±6.0 A/F
80.01 to 100.0 A/F: within ±9.0 A/F
100.1 to 150.0 A/F: within ±20.0 A/F
150.1 to 200.0 A/F: within ±38.0 A/F

Response time

Typical 80 ms (Max.150 ms)

Digital input-output

RS-232C (standard)

Analog output

0 to 5 V DC (scaling possible)

H/C setting range

0.00 to 9.99 (key selectable)

O/C setting range

0.000 to 6.811 (key selectable)

Calibration gas

Ambient air or standard gas

Acceptable vibration

0 to 294 m/s2


10-30 V DC, 50 W


130 (W) × 170 (D) × 75 (H) mm


Approx. 1.1 kg (Control unit)

UEGO Sensor (Data sheet supplied with each UEGO sensor)

Sample gas temperature

-7℃ to 900℃

Heater temperature control


Hexagonal nut size

22 mm



Standard accessories

UEGO sensor (1), Sensor cable 10 m (1), DC power cable (1), Analog output cable (1)


AC unit PSU-700, Two-channel rack kit (incl. AC power adapter), Sensor cable (5 m, 20 m), Calibration unit, Nut for attaching sensor, Closing-up bolt, RS-232C cable


Dimensional outlines (units: mm)
Dimensional outlines (units: mm) UEGO Sensor