A non-dispersive, optic-electrical filter instrument is described, which combines high spectral
resolving power (~ 0.1 Å) with large luminosity, at wavelengths which are of interest in …

A method is described to reduce the Brownian deflections of electrometer systems. This is
achieved by replacing the air damping by a special type of artificial damping. The latter is …

In § 2 the equation of motion of an electrometer appears to be of the 3rd order. For sufficient
high labilisation, critical damping occurs at two values of the resistance R of the measuring …

The relation between the rate of photosynthesis and the pigment content was studied in
seedlings of Avena sativa var. Victory. Etiolated seedlings were illuminated during different …

In the present article we shall derive the natural precision for the measurement of radiation
with a bolometer ie the highest precision obtainable with the circuit. In addition we calculate …

The development, since 1935, of a photoelectric amplifier backed by an ac galvanometer is
described. The accuracy attained is equal to that of an ideal dc amplifier. The ac amplifier, …

Page 1 THE ELECTRONIC EXCITATION-FUNCTION OF THE METASTABLE Ss-LEVEL OF
NEON by JMW MILATZ and LS ORNSTEIN (Communication from the Physical Laboratory of …

AgCl crystals were irradiated with monochromatic β-rays in a magnetic β-ray spectrograph.
The results show that under suitable experimental conditions in the crystal all β-rays of a …

The relative excitation-function of the metastable 2 3 S-level of helium has been determined
by means of absorption measurements. It is shown, that the dependance of the absorption of …

By using a compensation method, the action spectrum (spectral distribution of stimulating
efficiency in a quantitative measure) of phototaxis in the purple bacterium Rhodospirillum …