Subject
- Infrared spectroscopy5
- Coins4
- Hydrogen-ion concentration4
- Scientists--Portraits4
- Amplifiers (Electronics)3
- Beckman Instruments, Inc. Spinco Division3
- Bridge circuits3
- Factories3
- Pins and needles3
- Rulers (Instruments)3
- Scientific apparatus and instruments--Maintenance and repair3
- Aerial photographs2
- Breakdown voltage2
- Buildings2
- Computers--History2
- Electric resistance2
- Electrodes2
- Electronic analog computers2
- Electronic data processing2
- Gases--Analysis2