? ? ???常溫pH計(jì)具有高低點(diǎn)繼電器，可通過(guò)設(shè)定高低點(diǎn)來(lái)控制加藥泵。當(dāng)常溫pH計(jì)儀表的顯示值高于高點(diǎn)設(shè)定值時(shí)，高點(diǎn)繼電器會(huì)吸合，高點(diǎn)報(bào)警指示燈亮。當(dāng)常溫pH計(jì)顯...