The HD 8602 is a combined instrument for measuring pH, mV and °C in the laboratory, in the field and in industrial plants. The instrument is provided with a BNC connector for pH electrodes, electrodes for measuring redox potential (ORP) or specific ion electrodes (ISE). Compared to a cable that cannot be detached from the instrument, the BNC offers the advantage of being able to use all the electrodes available on the market and especially those types which for cost reasons do not have a connector directly on the electrode. Furthermore, with the BNC connector it is possible to disconnect the pH measuring cable (ORP, ISE), so that temperature can be measured alone without the electrode connecting cable getting in the way. The TP 870 temperature measuring probe is connected to the instrument by means of a 8-pole DIN connector. During pH measurements this probe automatically compensates the electrode temperature coefficient. If the temperature sensor is not connected, the temperature coefficient may be compensated manually. A mechanical push-button panel protected by a polycarbonate membrane offers the possibility of selecting the desired unit (pH, mV or °C). Adjustment of asymmetry (pH) and (slope) in pH measurements is also carried out on the push-button panel. During the calibration phase (CAL) the symbols on the display flash. To return to the measuring mode, push the CAL button again. The calibration data are momorized even when the instrument is turned off. When the HOLD button is pressed the reading on the display is blocked; when the HOLD button is pressed for the second time the instrument returns to normal operation (continuous updating of the reading). To turn the instrument on or off, press the ON/OFF button. The instrument will also turn itself off automatically after about 8 minutes if it is in the measuring mode. Automatic cut off in the measuring mode may be avoided by pressing HOLD+ON/OFF when you switch on the instrument.