A Bridged Tee Detector for Nuclear Magnetic Resonance

Abstract

The circuit of a bridged tee network for the measurement of nuclear magnetic resonance is described. This circuit was used to measure the field strength of a large air core solenoid. The balance equations for the bridged tee network are: $$\begin{array}{c}{W}^2\text{=1/L}\left(\frac{C_1{C}_2}{C_1{\mathrm{+C}}_2}\right),\\ \mathrm{R=}\frac{L}{{\mathrm{(C}}_1{\mathrm{+C}}_2)}\mathrm{r.}\end{array}$$ The probe contained one ml of No. 20 lubricating oil with B and S No. 17 copper wire wound directly on the proton sample cell to give convenient resonance capacities and a convenient resonant impedance (500 to 25,000 ohms) near the 20‐mc working frequency. The simplicity of construction, the general utility, and the adaptability to ordinary laboratory apparatus prove the circuit to be excellent for detecting nuclear magnetic resonance.