A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at http://www.rbdinstruments.com
year, RBD introduced an updated 9103 USB Picoammeter, with 3 new
High-speed: 500 reads / second compared to 40 for the Standard Model
High-voltage: an isolated signal input with the ability to float the 9103 Picoammeter to ±5000 VDC.
High-speed / High Voltage: One model combining both features.
This year we’ll be working on adding new features to our Actuel application software and providing more comprehensive support and programming documentation.
Actuel 1.6 is Released
The latest version of Actuel (1.6) is now available, as is an updated User Guide. The guide has new information on setting up and programming the 9103 for high-speed communications. Both can be found here.
This release replaces the Beta release and has full support for high-speed sampling and data recording and graphing.
TechSpot Article Series
This year, we’ll be running a series of articles here on the TechSpot blog with more information on the new 9103 models and features, as well as detailed configuration, application, and programming advice.
of the topics we’ll be covering include:
the 9103 for high-speed data collection
the high-voltage reference
use of the input ground
Keep your eye on here on TechSpot for these and other articles covering all of RBD’s products, and please consider subscribing.
The 9103 USB picoammeter is often equipped with a +90 V bias option which improves the accuracy of electron and ion current measurements (by reducing the number of low energy secondary electrons that are generated by the beam from leaving the target).
The +90 V bias comprises two 45V batteries in series which are located inside the 9103 chassis. This blog post will explain how to test and replace the batteries in a 9103 picoammeter.
1. Connect a DVM (digital volt meter) to the 9103 Input BNC connector. A BNC to double banana cable works well. Set the DVM to DC volts.
2. In Actuel (the 9103 software), select the input Grounded and bias On.
3. Sample the current.
4. When the bias ON is checked there will be about +90V DC on the input of the 9103.
5 .The input impedance of most DVMs when measuring DC voltage is 10 meg ohms. The two 45 volt batteries should total 90 to 95V DC. The bias voltage divided by the input impedance of the DVM will equal the current. In this case the voltage of the two 45 volt batteries totaled 94V and the current was 9.414 uA.
9.4 uA in Actuel
94 V DC on DVM
6. It is recommended that the bias batteries be tested every 6 months and replaced when the voltage drops below 80 volts. It is normal for the batteries to wear out over time and with use. Once the bias voltage drops to less than 50 V the effectiveness of preventing secondary electron emission is greatly reduced, which in turn reduces the accuracy of electron and ion beam current measurements.
The RBD part number for the 45 V battery is BAT-45-213.
Whether you have an RBD 9103 USB picoammeter or an older Keithley with a PHI model 78 bias box, you should test the batteries as part of your preventive maintenance procedure and replace them as needed.
To replace the batteries in a 9103:
Unplug the 9103 USB power and input cables.
Using the Torx wrench that was included with the 9103, remove the screws from the front and rear 9103 chassis covers.
Slide the board out from the front of the 9103. You will need to rotate the back cover to feed it in. The back cover has a ground wire that is attached to the 9103 board. Also note which groove the 9103 board is in as you will need to put it back in the same groove.
Remove the battery support bracket (white plastic).
Carefully remove the old batteries.
Install the new batteries.You may need to adjust the contacts on the batteries to get them to fit onto the board snaps more easily.
Reattach the battery support bracket.
Carefully slide the back cover and board back into the chassis. Make sure that you put the board back in the same groove that it came out of. If the front cover does not line up with the chassis then you are not in the correct groove.
Reattach the screws to the front and back covers. Do not over tighten the screws!
Once you have installed the new batteries, test the voltage. You should have 90 to 95 Volts.
The latest software releases of Actuel for the 9103 Picoammeter and CMapp for the microCMA now support the ability to automatically read target current when acquiring data.
To use this feature, you must (of course) have a 9103 Picoammeter running RBD’s Actuel software.
Run CMapp for the microCMA, select Hardware Properties from the System menu, and check the option “Use 9103 Picoammeter to read target current.” You only have to do this once.
Turn on the 9103 Picoammeter, run Actuel, and measure your target current as usual. Leave Actuel open. It doesn’t matter whether the 9103 is sampling, but keep in mind that your current settings (sample rate, etc.), will be used.
Now, whenever you take an acquisition (except for an alignment), the target current will be measured at the beginning of the acquisition and displayed with the other electron gun settings when the acquisition is complete.
If you don’t have a 9103, you can still manually enter a value for the target current in the acquisition dialog.
Download the latest release of Actuel for the 9103 Picoammeter here.
Download the latest release of CMapp for the microCMA here.