Conductivity Meter

• Conductivity: Range 0–75 mS/cm 

• Accuracy: ±0.3 mS/cm 

• Response Time: 15 seconds 

• Salinity: 0-40 ppt 

• Temperature: -7.5 to + 41°C 

• Temperature Accuracy: ±0.1°C 

• Pressure range: 0-100kPa. abs 

• Accuracy: 0.2% of range 

Monitoring the vertical conductivity and temperature profile of the water is of significant importance to oceanographers and marine biologists in their study of the sea. The Conductivity Meter is a versatile instrument designed to measure and record these parameters at regular time intervals. The instrument is moored in a fixed position and can operate for long periods. It consists of a 12-channel datalogger and a string with up to 5 Conductivity / Temperature sensor. The are clamped to the string by a fastening fixture. The sensor string, which has a strain member, is terminated at the data logger with a strain - data logger is housed in a standard pressure case and contains all necessary functions and electronics to scan and store the parameters at user selectable time intervals. All electronics are molded in low density polyurethane foam.

When triggered, the datalogger will scan each sensor in sequence, starting with the sensor nearest the logger, and convert the readings to 10-bit data words ( PDC-4 ). These are stored in the Data Storage Unit. Simultaneously, an acoustic transducer transmits the same data words into the water, thus providing in-situ monitoring of data on the surface by means of a Hydrophone receiver.

An electrical terminal on the top end-plate gives access to the same data signals that are being stored in the DSU, a convenient feature when calibrating and testing the instrument. The first channel gives a reference reading identifying the datalogger and the recorded data. The reference number also serves as a check of the datalogger’s performance. When the last channel is read, the logger goes quiescent, waiting for the next trigger pulse to arrive. Time and date for the first measurement cycle and subsequently for every measurement after midnight are also recorded in the DSU. After the measuring program is completed, the stored data are easily read by a PC.