The LABOTRIX ACIDO G11 electronic pH meter is a wireless digital acidity sensor with its own colour screen that determines the pH of liquids and aqueous solutions, that is the acidity or alkalinity of a medium. It is used in practical, laboratory and field lessons for studying water and soil extracts, household acids and alkalis, buffer systems, and for observing the change of pH during acid-base titration. The device is intended for chemistry, biology, natural science and geography classrooms and for STEAM laboratories of general secondary education institutions. It is a teaching aid, and its readings are not intended for industrial, medical, research or commercial measurement.
The meter covers a measurement range of 0.00 to 14.00 pH with a scale step of 0.01 pH and a measurement error of ±0.1 pH; the operating temperature of the device is 0 to 60 °C. The colour liquid crystal display has a diagonal of 1.8 inches and forms the reading directly on the device at the moment of measurement, so a computer, a separate analogue-to-digital converter or connecting wires are not needed to obtain a result during an experiment. The unit is a monoblock controlled by five function buttons and powered by a built-in removable rechargeable battery, so it works autonomously; results can additionally be transferred to a terminal, computer, tablet or cloud over the wireless channel or over the high-speed USB wired interface, with iOS, Android and Windows supported. The sensing element is a glass combination pH electrode with a semi-permeable glass membrane, attached through one quick-release connector compatible with standard sensors of the system and replaceable by the user without tools; the outer filling solution of the reference electrode is potassium chloride at a concentration of 3 mol/l, and calibration is performed against standard buffer solutions at two or three points of the scale. The body has a mount for a laboratory stand, the software interface is in Ukrainian, the marking and operating documentation are in Ukrainian, the service life is 5 years and the warranty period is 12 months.
The set includes a wireless acidity sensor with a colour screen — 1 pc, a replaceable glass combination pH electrode — 1 pc, a storage bottle for the electrode with a protective cap — 1 pc, potassium chloride solution 3 mol/l — 1 bottle, a set of buffer solutions for calibration, a protective case for storage and carrying — 1 pc, a USB cable — 1 pc, a laboratory stand mount — 1 pc, an operating manual — 1 pc, a passport with a warranty card — 1 pc, and individual transport packaging — 1 pc. The number of buffer solutions and their pH values are stated in the packing list of the particular version of the product, as are the overall dimensions, weight, battery capacity and battery running time; a charger is supplied depending on the version, and multi-sensor kits include a shared charger for four sensors. Distilled water, a wash bottle, laboratory glassware, reagents and filter paper are not included and are prepared by the educational institution. The product needs no assembly — the electrode is connected to the unit before the first measurement.
Calibration against buffer solutions is a mandatory operation before measurement, and it is repeated at the start of each lesson, after replacement, cleaning or long storage of the electrode, after a change of temperature conditions and before moving to samples from another part of the scale. Before work the filling port on the side tube of the electrode is opened, the level of potassium chloride solution is checked, the tip is rinsed with distilled water and the drop is removed by a light touch of filter paper; the electrode is then immersed so that both the glass membrane and the diaphragm are under the liquid, the solution is stirred gently and the reading is taken once it has stabilised. Between samples the electrode is always rinsed, and after the lesson it is capped with a small amount of potassium chloride solution 3 mol/l, since the membrane is never left dry.
Preparation, calibration and electrode maintenance are performed by the teacher or laboratory assistant, and students work with the device after a safety briefing and under supervision; goggles, gloves and a laboratory coat are used when handling acids and alkalis, and hot solutions, melts and concentrated acids and alkalis are not measured. The measuring unit is wiped with a dry or slightly damp soft cloth and is never immersed in liquid or washed under running water, and the glass membrane is never rubbed or scraped. The product is stored in its protective case in a dry heated room at a temperature of +5 to +40 °C and relative humidity of 80 % without condensation, away from direct sunlight, dust, heating appliances and vapours of acids and alkalis, and it is transported in the factory packaging with the electrode kept in its storage bottle. The product is used only under the supervision of a teacher and is recommended for students from the age of 10, that is grade 5 and above.
