Food-SSAFE Spetrum / Sample Analysis and Food Examination Kit Operation Manual Berkeley Nucleonics Corp 2955 Kerner Blvd., San Rafael CA 94901 Tel: 415-453-9955 Fax: 415-453-9956 Email: info@berkeleynucleonics.com Website: www.berkeleynucleonics.
b. On the Connection screen confirm that COM 1 is indicated and tap OK to continue. The screen will close and after a few moments a message will pop up showing the serial number of the connected MODEL 970. Acknowledge that message by tapping OK. c. Next the Detector Selection screen will be shown. Confirm that your detector serial number is shown and tap Use This Detector to continue. d. The Detector Settings screen is displayed. Tap the OK button to continue.
e. When the Main Screen is displayed the system is ready to operate. 4. Gain Stabilization and Source Check Note: Prior to measuring samples the software requires that a gain stabilization and source check be performed. It is possible to bypass or shorten these requirements by using the manual gain stabilization function instead of the automatic gain stabilization, although bypassing the automatic gain stabilization is not recommended (discussed later in the section Bypassing Startup Requirements).
b. The Automatic Gain Stabilization screen will be displayed. The software will collect a spectrum until a sufficient number of counts exist to determine a statistically reliable peak center. If not within a few channels of the expected location the fine gain will be adjusted in the appropriate direction and an additional count started.
. Taking a Background Measurement a. Remove the detector from the shield, take the lid off the shield, remove the K-40 standard, and recover the Marinelli spacer from the standard. b. Place the spacer into a clean, empty Marinelli. Put the Marinelli into the shield, replace the cover, and put the detector through the hole in the shield. c. From the Util menu select Acquire Background… d.
f. Tap the green circle “GO” icon (or UTIL|Start Acquisition) along the bottom of the screen to begin analyzing a sample. The Sample Data screen will be displayed. Enter the acquisition time desired (default is 900 seconds or 15 minutes). Select the appropriate sample matrix--SOIL, WATER, or FILTER--and the relevant sample geometry— MARINELLI or DISK. Note: The Food-SSAFE comes calibrated for water and soil in a (nominal 500 mL) Marinelli geometry plus a 2” filter in a disk geometry.
Basic Functions of the Main Screen The Main Screen is divided into three sections. The top section (colored blue by default) is the Spectrum Display. a. Colors for the background and spectrum trace (as well as for other items) can be changed using View|Preferences. b. Tapping the Spectrum Display will cause a line to be displayed at the tapped location. The channel number and number of counts in that channel will be displayed.
manufacturer, model, serial number, and the detector description. The final line contains relevant information on acquisition status, background status, etc. f. The bottom section of the screen contains the menu items and button bar. The menu items will be discussed in detail in the next section. The button bar consists of a green circle (grayed out when an acquisition is active), a red circle (grayed out when not actively acquiring a spectrum), and a black X.
d. Util|Detector Settings opens the Detector Settings screen. The hardware settings (HV, Threshold, Shaping Time, Input and Polarity, Coarse Gain, and Fine Gain) can be modified as needed to make the spectrum display suit your needs and purposes. The proper settings for these items were set when the initial calibration and should generally not be altered. This is because changes to these hardware settings will dramatically affect detector response, invalidating any calibrations done so far.
right arrows to adjust the location of the line to the center of the second peak, and then enter the energy. Repeat this process for up to 12 energy calibration points. Note: It is not strictly necessary to enter the calibration points in any order. When the energy calibration is performed the calibration points will be sorted in order of the channel values, from lowest to highest. When all energy calibration points have been entered, tap the Do Energy Calibration button.
