Abstract: Resonator sensors namely piezoelectric benders are used for sensing fluid viscosity and density. The benders are inserted into a liquid to be monitored. An input voltage is applied to the bender causing it to vibrate in the liquid at a resonant frequency. Output voltage amplitude or frequency are monitored to determine changes in viscosity and density, respectively. The device may be used as a liquid level sensor and to control alteration of the viscosity of the fluid as, for example, by connection with a supply of ink or solvent in an ink jet printing device.

Abstract: A method and apparatus for accurately determining and setting the optimal nozzle drive voltage for an ink jet printer. The current carried by charged test drops is monitored by a sensing electrode and ammeter while the nozzle drive voltage is slowly varied between minimum and maximum points. A plot of drop current versus nozzle drive voltage provides an accurate determination of the good printing window for the particular nozzle under the operating conditions presented. This arrangement can be used for calibrating a new nozzle in an existing printer or for calibrating a new ink or font to ensure that operation will occur within the desired print window.

Abstract: A control system is disclosed for an ink jet printer. The control system employs acoustic transducers to determine the velocity of sound in the ink and in a reference chamber containing only fresh ink. By comparing the two measurements it can be determined when to add additional solvent to the system to maintain solids concentration substantially constant.

Abstract: A method and apparatus for generating scintillation pulse height distribution spectrum with respect to a square root representation of pulse height. Pulse height data are pooled into variable size windows of which the average energy level is approximately proportional to the square of the corresponding window number. The square root representation is accomplished by choosing the size of each window according to an arithmetic series of a constant difference between windows.

Abstract: A method and apparatus for improving signal to noise in an electropherogram acquired by electrophoresis. The migration time is remapped by binning the data with respect to migration time to improve signal to noise and peak resolution. The data points of the electropherogram are pooled into variable size bins, each corresponding to a number of time intervals. The sizes of the bins increase with migration time. To further improve signal to noise and peak resolution, the binned data is filtered by Fourier transformation. The present invention allows for accurate determinatiion of DNA sequences.