MEASURING PH WITH HIGHLY RESISTANT MEASURING DEVICES
Abstract
PH measuring devices can be divided according to type into two main classes. In the first group, the measuring voltage is fed directly to the indicator dial after amplification. A directly coupled or a modulated amplifier can be used, a combination of both also being possible. The second main group works on the compensation principle. The measuring voltage is placed opposite a variable, calibrated compensation voltage and alternated until the difference voltage is zero. The control of the compensation current can be manual or automatic by means of a servo mechanism, the latter method often being combined with a registering device (compensograph).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1963
- Accession Number
- AD0836219
Entities
People
- Hans J. Wolf