3540 Bench Combined Conductivity/pH Meter
The 3540 is ideal for use in all laboratories where pH and conductivity analyses are required. The setup menu gives quick and easy access to the whole range of instrument, pH and conductivity measurement options. Calibration of both channels is automatic, with the option to select 1, 2 or 3 calibration points. The pH channel can also display mV values if required.
Display and Controls
The model 3540 has a back lit 1/8 VGA dot matrix LCD. In normal measurement mode the left-hand side displays the conductivity value and the right hand side the pH value. Both channels have their own temperature/ATC input displayed below the measured value, making them fully independent. The display includes a number of icons and prompts used to inform and indicate to the user the instrument status and measurement conditions. The operating system is based around five separate screens, each of which can be displayed by moving the cursor along the tabbed menu bar at the bottom of the display.
The simple keypad controls all the functions of the instrument. The ON/OFF key operates as an escape [ESC] key at sub-menu levels, each press returning to the next highest level until the main measurement screen is reached, where a further press will switch the instrument off.
Pressing the CAL key initiates the calibration sequence for the channel highlighted on the tabbed menu bar. The calibration sequence will be based on the options selected in the relevant calibration set up menu. When recalling results, with the Results tab highlighted, the CAL key functions as a Clear [CLR] key, returning the function defined for the Clear key in the data logging set up menu.
The Print key outputs the currently displayed measurement, stored results or statistics screen to the RS232 serial port, where it can be printed on the optional serial printer. An option to print the measurement displayed on one or both channels can be selected in the Printer Set Up menu.
The Enter key confirms selections as they are made in the set up menus. With the measurement screen displayed it acts as the Store [STO] key and stores the current readings in the internal memory. Up to 250 pH and conductivity readings can be stored. The action taken when the memory is full can be selected in the data logging set up menu.
The four Cursor keys enable easy navigation through the set up menus, as well as selection of the required screen on the tabbed menu bar. The Up or Down Cursor keys are also used to select alternative measuring modes from the highlighted channel on the main measurement screen.