Electronic Self-test for Epsilon Detectors
The epsilon detector contains two built-in resistors that can be substituted for the analytical flowcell. This will allow you, in conjunction with BASi technicians, to verify that the instrument's circuits are performing properly. Such a test can aid in determining whether performance problems are related to the application, the flowcell, or the instrument's electronics.
The test involves switching to the test resistors, running a set of pre-configured test methods, and comparing the resulting chromatograms with expected results. YOU MUST THEN SWITCH BACK TO THE ANALYTICAL FLOWCELL to return to normal operation.
PREPARING FOR THE TEST
Before running the test you must obtain some basic information about the hardware and software versions in the epsilon (Equipment Options), and the number of channels of data collection available (Number of Analog Boards).
EQUIPMENT OPTIONS. Obtain the list of equipment options by opening the Data/Equipment Options drop-down menu from the main screen of Control:
Make sure that the list indicates ROM version Epsilon 1.70 or greater. The self-test will not run on earlier versions.
Make a copy of this information by holding down the Alt-key and pressing the Print Screen key of your keyboard. Then open either a word-processing program, a spreadsheet program, or an image-manipulation program and paste (Ctrl-V) the copied image. You can then save and/or print the image.
NUMBER OF ANALOG BOARDS. Obtain this information by opening the Method/Data Acquisition Options drop-down menu from the main screen of Control, then pressing the 'Change' button:
You need not copy this information, just note the number of analog boards indicated at the top of the screen. It will be either one (one-channel of data collection), two (two channels) or three (four channels).
RUNNING THE TEST
Running the self-test requires five steps:
- Switch to test resistor 1
- Load, Equil, and run a Method for resistor 1
- Switch to test resistor 2
- Load, Equil, and run a Method for resistor 2
- Switch back to the analytical flowcell
SWITCH TO TEST RESISTOR 1
Open the Control drop-down menu and select 'Test Mode Resistor 1':
NOTE:
If you are controlling a BASi pump, your previous flow rate will remain in effect during the test. You will not be able to change any pump parameters until you exit Test Mode and resume normal operation.
LOAD AND RUN A METHOD FOR RESISTOR 1
Open the Method/Save Method drop-down menu and save your current Method to the directory you normally save Methods to.
Open the Method/Load Method drop-down menu and migrate to the Self-Test directory, typically C:\BAS3\Selftest. There will be three Methods for test_one, labeled for the number of analog boards:
| Boards | Method |
| 1 | one_board_test_one.MTH |
| 2 | two_board_test_one.MTH |
| 3 | three_board_test_one.MTH |
Load the Method that corresponds to the number of analog boards in your instrument, as determined above.
Optional — Change the Run Number: The Method is configured to save the data as run 1. If you have used the self-test before, and wish to retain the previous results, open the Method/Data Acquisition Options drop-down menu and change 'First run number' to whatever you wish (except 999, the run number under which we've saved specimen 'normal' runs).
Run the Test: Press the 'Equil' button in the Run Status box, then the unzero button in the Detector Status box, then 'Run' in the Run Status box.
Data collection will begin, and last for slightly more than a minute. The one-board Method will collect one channel of data (A), the two-board Method will collect two channels simultaneously (A and B), and the three-board Method will collect four channels simultaneously (A, B, C, and D).
SWITCH TO TEST RESISTOR 2
Open the Control drop-down menu and select 'Test Mode Resistor 2':
NOTE:
If you are controlling a BASi pump, your previous flow rate will remain in effect during the test. You will not be able to change any pump parameters until you exit Test Mode and resume normal operation.
LOAD AND RUN A METHOD FOR RESISTOR 2
Open the Method/Load Method drop-down menu. There will be three Methods for test_two, labeled for the number of analog boards:
| Boards | Method |
| 1 | one_board_test_two.MTH |
| 2 | two_board_test_two.MTH |
| 3 | three_board_test_two.MTH |
Load the Method that corresponds to the number of analog boards in your instrument, as determined above.
Optional — Change the Run Number: The Method is configured to save the data as run 1. If you have used the self-test before, and wish to retain the previous results, open the Method/Data Acquisition Options drop-down menu and change 'First run number' to whatever you wish (except 999, the run number under which we've saved specimen 'normal' runs).
Run the Test:
Press the 'Equil' button in the Run Status
box, then the unzero button in the Detector Status
box, then 'Run' in the Run Status box.
SWITCH BACK TO THE ANALYTICAL FLOWCELL
Open the Control drop-down menu and click on the 'Analytical Flowcell (Normal Operation)' line:
Then open the Method/Load Method drop-down menu, change to the directory where you save your Methods, and load your original Method. Use the warmup feature to equilibrate your flowcell.
EVALUATING THE RESULTS
A detailed analysis of the results should be conducted by BASi technicians. But in general, if the output for all channels looks like this, the epsilon electronics are most likely working properly:
For comparison, the following specimen data sets have been placed in the Selftest directory. Use ChromGraph Report to load and compare your data set against the matching specimen data set:
| Boards | Channel | Data Name |
| 1 | A | one_board_test_one999A.DAT |
| 1 | A | one_board_test_two999A.DAT |
| 2 | A | two_board_test_one999A.DAT |
| 2 | A | two_board_test_two999A.DAT |
| 2 | B | two_board_test_one999B.DAT |
| 2 | B | two_board_test_two999B.DAT |
| 3 | A | three_board_test_one999A.DAT |
| 3 | A | three_board_test_two999A.DAT |
| 3 | B | three_board_test_one999B.DAT |
| 3 | B | three_board_test_two999B.DAT |
| 3 | C | three_board_test_one999C.DAT |
| 3 | C | three_board_test_two999C.DAT |
| 3 | D | three_board_test_one999D.DAT |
| 3 | D | three_board_test_two999D.DAT |
