| 摘要 |
FIELD: metrology. ^ SUBSTANCE: invention can be used for determining the concentration of salts dissolved in water. The water quality indication device incorporates variable signal generator 1 arranged in the casing, differential amplifier 5 loaded onto precision detector 6 connected to indication unit 7, power supply 10, voltage source 2 controlled by the voltage making the load of generator 1 built around a negative feedback operational amplifier and resistor element 4. The electrodes of pickup 11 and resistor element 4 are connected in series to the output of voltage source 2, the said resistor element being connected to the input of operational amplifier 5. Variable signal generator 1, voltage source 2, differential amplifier 5, precision detector 6 and indication unit 7 are connected to power supply 10. ^ EFFECT: improved linear characteristics, stable measurements, simpler design, ease of use. ^ 3 cl, 4 dwg |
