Model 400 User Interface

The SofTA Model 400 is controlled from a 6.5” diagonal measure color TFT LCD touch screen display.

Control of the Model 400 is achieved via two screens; Control Panel and Chart View. Control Panel provides the means to set the detector operating, data collection, and method conditions. The Chart View provides a means to view the detector signal in real time, access to the help menu and memo functions.

Control Panel

Control Parameters

ELS Detection Signal (V): The largest number in the window indicates detector signal voltage.

Raw Signal and Baseline: These two radio buttons change the value displayed under the larger voltage signal. The baseline number is the value subtracted from the raw signal for baseline correction. Because of the auto-zero function, a baseline problem may be hidden from the ELS detection signal readings. The two readings provide diagnostic information. For example, if the baseline reading is much higher then during previous operation the exhaust tube adaptor may not be properly installed or mobile phase is not being effectively evaporated or the optical cell (or the light trap) is dirty and needs to be cleaned.

BLN Tracking: This check box turns on and off baseline tracking. If the box is checked baseline tracking is active. Baseline tracking monitors the detector signal and electronically corrects for baseline drifting. The use of baseline tracking will result in a smooth and flat baseline. BLN Tracking does not affect the peaks.

Gas Pressure (psi): This window displays the gas pressure entering the detector. The light will be green if the value is stable and within the acceptable parameters. If the light is red, confirm that the gas on icon is displayed then adjust the incoming gas flow until it is within acceptable parameters and the light is green. The light will be yellow when the detector is in standby mode.

Exhaust Tube Temperature (°C): This window displays the actual temperature of the exhaust tube. The light will be green if the temperature is within the acceptable parameters. If the light is red, the temperature is not within acceptable parameters. Wait for the temperature to reach equilibrium. The light will be yellow when the detector is in standby mode.

Optical Cell Temperature (°C): This window displays the temperature of the optical cell. The light will be green if the temperature is within the acceptable parameters. If the light is red, the temperature is not within acceptable parameters. Wait for the temperature to reach equilibrium. The light will be yellow when the detector is in standby mode.

Drift Tube Temperature (°C): The bottom window, “Read”, displays the actual drift tube temperature. The top window, “Set” displays the temperature set point. To change the temperature set point, select the parameter, then use the up and down buttons to change it. Tap “Save” to apply the new set point. The light will be green if the temperature is at or near the set point. If the light is red, the temperature is not within acceptable parameters. Wait for the temperature to reach equilibrium. The light will be yellow when the detector is in standby mode.

Spray Chamber Temperature (°C): The bottom window, “Read”, displays the actual spray chamber temperature. The top window, “Set”, displays the temperature set point. To change the temperature set point, select the parameter, then use the up and down buttons to change it. Tap “Save” to apply the new set point. The light will be green if the temperature is at or near the set point. If the light is red, the temperature is not within acceptable parameters. Wait for the temperature to reach equilibrium. The light will be yellow when the detector is in standby mode.

Filter Weight: These radio buttons select the level of the signal filter used for data smoothing. The larger the number the higher the signal correction. “OFF” can be selected for no filtering.

Gain: These radio buttons select the gain level. There are two gain settings: norm and low. The "Low" setting results in signal 10 times lower than "Norm". If the sample concentration is too high, the detector input A/D converter will be saturated, appearing as a flat top peak. In this case, switch to low gain to keep the signal on scale.

Full Scale: These radio buttons select the full-scale level of the analog signal output. Choose 5 V or 10mV. Please notice that the selection of FS affects neither the ELS Detection Signal reading nor the chart scale on the Chart Screen which always correspond to 5V full scale.

Method: These radio buttons select the number of the methods saved previously. The top window displays the currently selected method. The middle window displays information regarding the method entered by the user. The lower window displays the actual detector conditions saved with the method.

Icons

System Status:

A happy face indicates the system is ready. A sad face indicates an error condition exists. A calm face indicates the system is in standby mode. Tap the face for information regarding the condition of the detector and recommendations to correct errors.

Standby Mode:

The night icon indicates that the detector is in standby mode. In standby the gas flow is shut off and all of the heaters are turned off. Tap the icon to switch between modes. Alternatively, instead of entering standby mode you can use the gas icon to shut off the gas when not using the detector.

Gas On/Off:

Tap this icon to turn the gas flow on or off as indicated.

Control Buttons

Large buttons are provided on Control Panel for easy touch-sensitive operation. Use “Select” button to make a selection. The title of a selected item turns blue. Use “Enter” button to enter Edit mode, which will turn the title red. Use the “+” and “–” buttons to change a value. Use the “Save” button to save and apply the changes. You can always use “ESC” button to exit without applying the change. The buttons at the bottom of the screen are used to set the detector parameters. The Control Buttons will change according to the parameter selected.

Select: Tap this button to cycle through the parameters in the Control panel.

ESC: exit edit mode without accepting the change.

+: Increase the selected parameter.

-: Decrease the selected parameter.

Enter: Used to enter edit mode so a value can be changed.

Save: Used to accept and store any changes made to a parameter.

Load: Load a method from detector memory.

Reset Baseline: Force the detector signal to be set to near zero.

Chart: Tap this button to switch to the Chart Screen.

Keyboard: Bring up a keyboard for entering descriptions of a method.