About Conductivity / Dissolved Solids or Resistivity Instruments
Conductivity / dissolved solids or resistivity instruments are analytical instruments that measure either conductivity, the amount of dissolved solids, or resistivity. Conductivity (in units of mhos/cm) is a measure of water's ability to transmit an electrical current. It is a gross, indirect measurement of the concentration of ions and consequently can be used to estimate total dissolved solids (TDS) levels. TDS is a measure of the dry mass (mg/l) of all the dissolved solids in water. Most of the colloidal particles will be included in a total dissolved solids measurement. Resistivity is the reciprocal of conductivity.
Sensors, detectors and transducers covers a wide category of devices used to monitor, measure, test, record, analyze and/or display data as generated due to changes in a measured norm. Major sensor and sensor switch categories include acceleration and vibration, acoustic, analytical, density and specific gravity, electrical and electromagnetic, encoders and resolvers, environmental, flow, force, gas, humidity and moisture, level, linear and orientation position, pressure, proximity or presence, rotary position, temperature, tension, tilt, torque, velocity, viscosity, and weather sensors.
Analytical sensors and switches are designed to analyze data based on components therein. Devices that search for dissolved solids, specific gases, gravities or densities, colors, or pH levels, etc. fall within this family. Specific instruments include conductivity sensors, dissolved gas apparatus, durometers, electrodes, hydrometers, pH sensors, pycnometers, resistivity sensors, rheometers, turbidity instruments, colorimeters, viscometers, and water quality analyzers.