ASTM E1064 Coulometric Karl Fischer Titration Trace Water Content Tester
Introduction:
The ASTM E1064 Water Content Tester is the newly developed full-digital intelligent trace water tester by fully taking reference of the advantages of domestic and foreign similar instruments. Based on coulometric titration principle, by adopting many advanced technologies and processes as well as brand new circuit topology structure design, GD-3200 is in accordance with many domestic and foreign standards, with advantages of high accuracy, quick electrolysis speed, short equilibrium time, accurate dummy deduct as well as accurate and reliable analysis result.
Main Parameters:
1. Electrolytic current: 400mA maximum
2. Measurement range: 3 - 9999.9 ug
3. Instrument resolution ratio: 0.1 ug
4. Accuracy: 3mcg water ±20% 10mcg water±10% 100mcg water±1% more than 100mcg ±0.5% (sample introduction error is not included)
5. Display: 7 inch high definition true color touch screen (1024*600)
6. Printing: wide line thermal printing
7. Power supply: AC220V±10% 50Hz±5%
8. Power: 100W
9. Environment temperature: 0 - 50ºC
10. Environment humidity: ≤85%
11. Volume: 390×270×220
12. Weight: 6kg
Work Principle:
Karl Flscher reagent reacts with water below:
12 + SO2 + 3C5H5N + CH3OH + H2O = 2C5H5N·HI + C5H5N·HSO4CH3
The reagent solution used is prepared by mixing simple substance iodine, I- and SO2-containing methanol, etc. The measurement is based on the conductibility of the equilibrium system consisting of simple substance iodine andI-. The following reactions proceed alternately on two electrodes when the current is imposed on them:
2I--2e→I2
I2 + 2e→2I-
There is an excess of I- in the solution, but the I- concentration change does not greatly affect the solution conductibility. The change of simple substance iodine concentration within a range will cause an effective change of the solution conductibility. We select the range in which the higher simple substance iodine concentration leads to the bigger change of solution conductibility, and measure the value of the current intensity generated by the voltage at both ends of the platinum electrode immersed in the solution. The current intensity reflects the solution conductibility. A sample is injected to the electrolyte. The water in the sample reacts. The tester can detect the iodine change in the reaction, while the tester can calculate the iodine consumption from the electric quantity consumed when the same amount of iodine is electrolyzed out. The mass of the water to be tested is directly indicated on the LED display. This tester has an electrolytic current autocontrol system, which can automatically control the electrolytic current according to the water content of the sample. The maximum electrolytic current is up to 400 mA. During electrolysis, the water content gradually reduces, and the electrolysis rate reduced proportionally till an equilibrium point. The corresponding control loop of end point of titration starts, and the tester stops of measurement accumulation. This system ensures high analysis precision, sensitivity and speed. In addition, some interference factors unavoidably exist during measurement. For example, blank current is generated in the titration cell because of the water immersed in air. However, this tester has the memory and subtracts blank current, so the mass displayed on LED display is the real water content of the sample.
GD-3200 Coulometric Karl Fischer Titrator: