connected electrically to meter 12 by a cable 18 terminated by a standard rs 232 connector the measured ph ise readings may be displayed by the meter 39 s display panel 12 a and the results of the calibration may be printed out by a conventional printer 22 connected by a similar cable 24 to apparatus 10 the ph ise electrode 14 which is a standard item of manufacture is basically a closed thin wall glass tube or vial about 12 mm in diameter filled with a reference liquid having a selected ph ise value the electrode includes a sensing bulb at the working end of the electrode a wire with a built in reference electrode reference junctions and usually also one or more temperature sensors when the working end of the electrode is immersed in a liquid an electrical potential is developed across the electrode contacts which reflects the difference in the ph ise values of the liquids inside and outside the electrode 14 that voltage is applied to the meter 12 which thereupon displays on its display panel 12 a the ph ise value of the liquid in which the electrode 14 is immersed the operation of ph ise meters is well known and therefore will not be described in more detail here but see the above referenced thermoorion catalog as shown in fig1 and 3 apparatus 10 includes a housing 30 having a rear section 30 a that supports a plurality of vented containers the illustrated apparatus 10 has four such.