Biological Sciences 330, Smith College | Research in Cellular Neurophysiology

Appendix: Using Gould TA240 EasyGraf Chart Recorders

Gould "EasyGraf" chart recorders

Our Gould TA240 chart recorders use thermal array technology: a fixed writing element composed of many tiny dots heats up a special paper to print the trace, the chart grid, and annotations. The chart recorders can write two channels of extracellular action potentials or other signals directly from the preamplifier. Each channel's vertical sensitivity is set by a combination of a pushbutton switch (x100, x1) and a dial whose units are "volts full scale" (this is the total voltage spanned by the entire width of the channel, not the volts per division as on the oscilloscope screen).

The chart speed is controlled by a set of pushbuttons at the top right. If you are not sure what speed to use, 10 mm/sec is a good setting to start with. The last important control is for channel position, just above the exit slot for the paper. The knob on the left controls channel 1, and a green LED array shows you the approximate position of the trace even when the chart is not moving. The knob on the right controls channel 2. Set each channel's baseline position so the displayed signals take up most of the chart. If you are not using a channel, pull out its position knob to turn off that channel's trace.

You should set the date and the time of day on the EasyGraf recorder if you have not already so. You should also turn on full annotation, so your chart records will automatically show the time they were made, tics for the time, the vertical sensitivity of each channel, and the chart speed. See the information below from the EasyGraf manual for instructions on how to turn on the timer and the annotation.

Excerpts from the EasyGraf Instruction Manual

Diagram of front panel

Start-up procedure

Typical application (includes setting date and time)

Diagram of chart annotations