The following items are in the data file labeled sample.log. This is a subset of the actual data taken. This is an ASCII file with the 28 items in a single line with spaces separating them. It is up to you to convert them to the format that you like. In general, the voltages are measured with respect to a common reference point, the ground at the ADC. The currents are measured by shunts which sit on a temperature controlled aluminum plate. The temperature is held to 0.01 C with 100 ppm shunt resistors. A current into the calorimeter is labeled positive. All temperatures are in C All currents are in amperes All voltages are in volts except Vpukplt "Date" The ASCII Date as 03-21-1993 "Time" The ASCII Time as 23:24:14 "Seconds" The time in seconds since the start of the run. Reaches values of several million so allow a proper variable. "Icathtr" The catalyst heater current in amperes. "Ipukplt" The puck - plate theremoelectric device current in amperes. This is the current that refrigerates the calorimeter insides. It is supposed to be constant during a run. Any variations are the result of an imperfect data system. We assume in the heat balance computation that the heat pumped out of the calorimeter is directly proportional to this current. Not a bad assumption for small changes. "Tpuck" The temperature of the puck. This is the nominal inside of the calorimeter temperature, and is regulated by a servo loop with a time constant of about 20 minutes. The voltage across the cell heater is controlled to hold Tpuck at the value requested by a DAC. "Tambient" The ambient temperature. A thermometer on the bench under a shelf so it is somewhat shielded from air currents. "Icelhtr" The anode and one side of the cell heater are connected together. This is the other end of the cell heater. This heater is imbedded in the aluminum spool piece that holds the cell. Typical thickness of the spool is 1/2" although it is much thicker at the top and bottom. "Tcat" The temperature of the catalyst area of the cell. The catalyst is in the top of the cell 5 mm glass tubes. Tcat is in a 10 mm glass tube surrounded by the catalyst tubes. Tcat is in the part of the 10 mm tub in the gas above the cell liquid. Tcell is in the same 10 mm glass tube, but at it's bottom where it is immersed in the liquid. The space between Tcat and Tcell is filled with foam pieces. "Tspool" Tspool is a thermometer in a drill hole in the side of the spool piece, about 1/2 way up the side. It is at approximately the liquid level. "Iadedrv" This is the sum of the currents into the anode and the cell heater. "Idummy" This is the dummy lead current. The dummy is a third electrode in the cell. It is normally run as a cathode. "Ichdtop" The current into the cathode lead. "Tcell" The cell temperature. This thermometer is in a 10 mm glass tube running down the centerline of the cell. Tcell is in the bottom of this tube which is normally under the electrolyte. The bottom end of the glass tube supports a fork structure which holds the cathode and which has the anode wound around it. "Vpukplt" Vpukplt is in millivolts, and is the voltage on the thermoelectric devices that sense the difference in temperature between the puck and the plate. "Vplttec" The voltage driving the plate-base thermoelectric device. This voltage will vary with external heat load on the calorimeter. If the ambient temperature decreases, this voltage decreases as the servo does not have to work so hard to pump heat out of the inner calorimeter. If the calorimeter inside gets hotter, then this voltage will decrease, as the servo wants to let the outer shell temperature rise, and so pumps less heat out of it. This is one of the most sensitive indicators that some heat has been released in the calorimeter. This will be indicated by a negative dip in Vplttec. "Vchdtop" The cathode voltage. "Vdummy" The dummy voltage. "Vadedrv" The anode voltage. "Vaderet" The voltage on the return lead of the cell heater. The other end of the cell heater is the anode voltage. "Vcathtr" The voltage on the catalyst heater. "Tshell" The temperature of the calorimeter outer shell. "Gas" Accumulated gas in cc. "Vcelgnd" The voltage at the ground braid where it leaves the calorimeter inside. "Tplate" The temperature of the plate. "Ipltbas" The current to the plate-base thermoelectric device. "Tbase" The temperature of the base. This is a measure of the cooling water temperature. "Vpuktec" The voltage driving the puck-plate thermoelectric device. This normally is constant as Ipukplt is always run at constant current. How to compute the calorimeter balance: Power is put into the calorimeter by the various voltages and currents treating it as a Kirchoff black box. Power is taken out of the calorimeter by the current through the puck-plate thermoelectric device pumping heat. Power In = Icathtr*(Vcathtr-Vcelgnd) + Iadedrv*Vadedrv + Icelhtr*Vcelhtr + Ichdtop*Vchdtop + Idum*Vdum Power Out = 19.453*Ipukplt Power in computed as above is positive, power out is negative. "anomalous heat" is then -(Power In + Power Out) The constant 19.453 is in watts per ampere and is determined by a calibration experiment. We welcome you to study the part of the run designed for determining this constant and arriving at your own preferred value. The "anomalous heat" is best seen by computing the integral of the energy over time. This is the sum over time of -(Power In + Power Out)*Delta Time. Delta Time is usually, but not always 60 seconds.