What type of water is specifically produced by deionizers?

Deionizers are designed to remove ions and charged particles from water, which results in water that has a high level of ionic purity. The process of deionization typically involves the exchange of cations and anions in the water with hydrogen and hydroxide ions, respectively, effectively reducing the concentrations of dissolved salts and other ionic substances. As a result, the primary characteristic of deionized water is its lack of ionic contaminants, making it particularly suitable for various laboratory and industrial applications where high purity is essential.

Other types of water mentioned in the options, such as sterile water or pyrogenic-free water, are defined by different criteria. Sterile water implies the absence of microorganisms, while pyrogenic-free water indicates a lack of substances that can cause fever (pyrogens), which is not exclusively addressed by the deionization process. Additionally, the presence or absence of micro-bubbles is not a defining characteristic of deionized water. Therefore, the correct answer highlights the focus on ionic purity, which is the primary function of deionizers.