Improving the measurement accuracy of temperature titrators requires starting from various aspects such as instrument calibration, operating standards, environmental control, and data processing. The following are specific operating techniques and precautions:

1、 Calibration and Maintenance of Temperature Titimeter Instruments

1. Regular calibration

Calibration of burette:

Use standard substances (such as reference reagents) to calibrate the volume of the burette, ensuring uniform flow rate of the titrant.

Record the deviation between the actual volume and the nominal volume of the burette and correct it in the calculation.

Temperature sensor calibration:

Use a high-precision calibrator (such as ± 0.1 ℃) to calibrate the temperature probe and avoid temperature measurement errors.

Check if the probe is clean to prevent sample residue from affecting sensitivity.

Calibration of pH meter or potentiometer:

Before titration, calibrate the potential system with standard buffer solutions (such as pH 4.0, 7.0, 10.0) to ensure measurement accuracy.

2. Instrument maintenance

Cleaning and maintenance:

Clean the burette, electrodes, and reaction vessel after each experiment to avoid cross contamination.

Regularly check whether the electrode film is intact (such as whether the glass electrode film is aged or damaged).

Pipeline inspection:

Ensure that the titration pipeline is free of bubbles or blockages, as bubbles may cause false endpoints or unstable flow rates.

2、 Operating specifications and techniques for temperature titrators

1. Sample processing

Temperature control:

Preheat the sample to the same temperature as the titrator (e.g. 25 ℃± 0.1 ℃) to avoid volume changes caused by temperature differences.

Use a constant temperature water bath or a heating stirrer to maintain stable sample temperature.

Uniformity guarantee:

Thoroughly stir or oscillate the sample to ensure uniform reaction (especially for precipitated or stratified samples).

2. Titration operation

Titration speed control:

When approaching the endpoint, reduce the titration rate (such as adding dropwise) to avoid excessive delay in the endpoint.

The automatic titrator can be set to "slow titration" mode (such as 0.1 drops/second).

Optimization of endpoint determination:

Select an appropriate endpoint determination method based on the characteristics of the sample (such as potential jump, color change, or thermal conductivity method).

Multiple judgment methods (such as potential+thermal conductivity signal) can be combined to improve accuracy for complex samples.

Repeated experiment:

Perform at least 3 parallel titrations and take the average to reduce accidental errors.

3. Blank experiment

Deducting background value:

Conduct blank experiments under the same conditions (such as using solvents instead of samples) and calibrate instrument background signals (such as potential drift or temperature fluctuations).