86
7.2.3 Modules
From the Service menu, touch the [Modules] tab.
The Modules tab displays the status of the probes, probe current for each enzyme probe, voltage for each ISE, and the
temperature. The probe current is expressed in nA (nanoamperes, 10
-9
amperes), a very low level of electrical current.
7.2.3.1 Flush
Touch the [Flush] button under Module 1 to flush the sample module with buffer. Observe the probe current values
(baseline). If they are above 6 nA, check to see if they are decreasing in value. Check the sample module; it should be full
of buffer. If necessary, touch the [Flush] key to flush the sample module again. Note that when the instrument is first
powered up, it may take several hours for the baseline currents to drop below 6 nA.
Touch the [Flush] button under Module 3 to flush the sample module with ISE buffer. Note that the instrument will purge
buffer to waste if the incorrect buffer is in the line.
Observe the ISE voltage values. They should be between -40 and 60mV and stable. When the instrument is first powered
up, it may take an hour for the voltages to stabilize.
7.2.3.2 Calibrate
The 2900 Series will automatically calibrate before running a sample batch. You may initiate manual calibration from the
[Modules] tab of the Service screen by touching the [Calibrate] button under each Module.
Calibration status is displayed on the screen.
Calibrate Module 1
