pH and ORP: Portable instrument MFD79

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The MFD79 is a compact measuring device, suitable especially for operative measurements in the field or industrial technologies, or for occasional use in the laboratory. The device is available with different input configurations, allowing simultaneous measurement of one or two quantities (with corresponding sensors) as well as temperature.

Operation of the device is easy thanks to the high-contrast dot-matrix LCD display, which is easy to read in the dark and in the sun, and a simple menu-based system controlled by only 6 buttons. Several levels of password protection protect the device against unwanted changes to the settings, or against unwanted interventions by less qualified operators or unauthorized persons. Semi-automatic calibration procedures greatly facilitate the preparation for measurements.

The MFD79 is suitable for a wide range of applications thanks to its small size and weight, high degree of protection and easily replaceable batteries of commonly available type (AA), with a long battery life ensured by low device consumption. In the field, the device and sensors are best protected by the recommended transport cover, which also protects against water immersion and drop damage (to some extent).

Log of measured values is an additional function that records the measured data in the device for later inspection (only on the device display). The data may also be displayed in the form of simple graphs.

An alternative for more demanding applications is the MFD80 instrument with extended range of supported measurements, support for data interfaces and a number of other improvements.

pH and ORP measurements

Classic glass sensors with an integrated reference electrode are used for pH measurement. The supplied sensors are equipped with plastic transport covers.

ORP can also be measured through the same input of the device if a corresponding sensor is connected. Separately stored calibration enables alternating measurements of both quantities (only one at a time).

Additional measurement of temperature

All inputs of the MFD79 device also support temperature measurement. Each connected sensor can therefore be equipped with an integrated temperature sensor, or a separate temperature sensor (type TTK21L) may be connected to any input. Any available temperature reading may be used for temperature correction of the measurement.

Dimensions120 x 65 x 22 mm
Weightca 200 g
EnclosureIP 54
Power supply2x AA size batteries (alkaline 3 V or NiMH 2.4 V)
Battery lifeca 300 - 1000 h (backlight off, depends also on configuration and battery type)
Data log capacitymin. 500 values
Digital interfacesnone
pH measurement range0 - 14
pH measurement accuracy± 0,5 % (of full range, at 25 °C)
pH calibration2 points
ORP measurement range± 1000 mV
ORP measurement accuracy± 1 mV
Temperature measurement range-4 to +50 °C
Temperature measurement accuracy± 0.2 °C