The langmuir trough and control electronics were obtained from R&K in Germany (http://rieglerkirstein.de). This photo shows the trough mounted on the X22B liquid spectrometer. Through the kapton exit window on the left, the front of the trough, barrier and wilhelmy balance are visible.
The trough, with its barrier motor and temperature controls, sits inside a quasi-gastight plastic box so that measurements can be done in helium atmosphere. The trough itself has teflon sides and a nylon base. Dimensions: 16cm x 60cm x 0.6cm. The barrier lies straight across the sides (rather than being fitted), and though this photo shows the wilhelmy balance mounted on the barrier fixture, we have moved it to the post at the front of the trough.
Control electronics:R&K Manual: | R&K Circuit #1 | R&K Circuit #2 | R&K Circuit #3:
The first pdf file above is a diagram with usage notes on wilhelmy balance calibration. The three circuit diagrams are for the pressure measurement, pressure/area control, and motor speed control units, which are on separate cards on the box. External BNC cables connect the three units across the front panel, as this photo shows.
The control box is mounted inside the X22B hutch, but unfortunately remote operation is not yet possible. The only exception is the capability to control the pressure or area setpoint from the computer (but to switch between the two, it's necessary to flip a manual switch on the box). However, analog output voltages are available so that pressure and area are always logged to the x-ray data file. We are considering a re-engineering enterprise to install remote operation, but given the way the box is designed this seems like it is going to be a real pain and is not a high priority.
Here are notes from the Vaknin Trough used in previous years.