Container for calibrating fluids, and device and method for measuring parameters of a sample of fluid, and oxygen electrode therefor

A liquid analysis device for measuring parameters of a sample of fluid, comprising:

• an analyzer and a control unit with a monitor, the analyzer comprising a measuring chamber with measuring electrodes, the measuring chamber being connected with closed, replaceable containers for holding calibrating fluids with a specified pH or partial pressure of gas as a reference and for holding working fluids and into which measuring chamber are introduced a sample of a measured fluid, control elements and operating elements to control the operation of the device and to maintain a constant temperature of the device, as well as computer processing elements for transforming results of measurements into quantities of parameters of the sample of fluid;
• wherein the device comprises elastic, impermeable, and exchangeable containers for the calibrating fluids, said containers having a connecting element wherein said connecting element is a self-tightening elastic joint ensuring tightness of a connection between the container and the device, said joint remaining closed during filling, storing, installing and using of the container in the device, whereby the calibrating fluids maintain a constant concentration of saturating gases during storage, installation and use of the container;
• and
• further comprising oxygen electrodes each comprising a Clark's electrode system, wherein an anode of the electrode system is made of an element selected from the VIB group of the periodic table system of chemical elements.

A liquid analysis method for measuring parameters of a sample of fluid, comprising the steps of:

• passing samples of a measured fluid, a calibrating fluid and a working fluid through a measuring chamber having at least two distinct and independent measuring channels at specified intervals of time as performed alternately and sequentially according to pre-planned steps in a proportional time-allocated measuring cycle;
• measuring physical-chemical properties of the measured fluid and of the calibrating fluids with sets of measuring electrodes;
• determining quantities of parameters of a sample of fluid on the basis of the measured properties;
• introducing standard aqueous solutions saturated with gases as well as oxygen taken from air as calibrating fluids for exposure to the measuring electrodes in the measuring chamber;
• dividing the calibrating fluid standard solutions alternatively with the measured sample of fluid and with the working fluids and in accordance with the measuring cycle among said at least two distinct and independent measuring channels disposed in the measuring chamber, each channel comprising a set of measuring electrodes for determining an acid-base equilibrium state in said fluid sample;
• and
• recalculating measurement results for each measuring channel in a common electronic system.