湖泊调查方法水环境英文授课.pptx

Introduction to Lake Surveys Basic Water Quality Assessment;Objectives;Basic water quality assessment;Insert a wonderful image that captures the joy of measuring physical and chemical profiles;Field profiles Sensors Temperature Dissolved oxygen pH Specific conductivity Transparency Secchi, turbidity Chlorophyll probes Light profiles Profiling guidelines/examples/helpful hints;Physical and chemical field profiles; ;Temperature – importance and reporting;Temperature probes;Temperature probes;Temperature probes;Temperature - calibration;Temperature - calibration;Temperature - troubleshooting;Temperature- field example;Dissolved oxygen (DO);DO – importance and reporting;DO – techniques;DO – techniques;DO – techniques;DO – probes;DO – probes;DO Probes - “older” polarographic sensors;DO probes and meters;DO probes – The WOW RUSS multiprobes;DO - calibration;DO - calibration;DO zero offset calibration;DO field measurements – precautions;DO field measurements – precautions;DO field measurements – precautions;temperature;DO Field profiles – supersaturation; ;;Note – if you get really good you can use this two-handed, no knees technique ;DO field measurements – helpful tips;DO field measurements – helpful tips ;DO field measurements – helpful tips;DO field measurements – helpful tips ;DO field measurements – error example;DO field measurements – error example;DO field measurements – error example;DO field measurements – error example;Specific electrical conductivity = EC25;EC25 - importance;Principle of measurement A small voltage is applied between 2 parallel metal rod shaped electrodes, usually 1 cm apart. Measured current flow is proportional to the dissolved ion content of the water. If the sensor is temperature compensated to 25oC, EC is called “specific” EC (EC25) ;EC25 – units;YSI 33-field conductivity meter (with metered, weighted cable).;EC 25 – probes;KCl is the typical standard Standard concentrations should approximate field values Dry solid KCl at 105oC for