The multifunctional, direct-reading calcium meter can not only measure the dosage of lime and cement, but also the content of active calcium oxide in the lime.
At the same time, after replacing the ion-selective electrode, the instrument can also be used as a standard ion potentiometer for electrochemical investigations or for the determination of other ions.
This instrument features 16-bit A/D converter, high input impedance design, stable data, and can input any ion selective electrode.
Calibration data can be stored in the instrument, recalibration is not required. A micro printer can be connected to print out the test results.
Measurement error check of the multifunctional direct-reading calcium meter:
In the actual measurement, the calibration instrument measurement error occurs due to various reasons. Here find an introduction to the inspection steps after a fault has occurred and how to determine the possible location of the fault.
This measurement system can be divided into three parts: instrument, electrode and solution. By checking separately, it can determine where the error occurs and then analyze it in detail to fix the error.
The inspection steps are as follows:
1. After turning on the instrument, a non-zero voltage value is displayed. Press the reset button. After clearing, the zero point no longer drifts, indicating that the instrument is normal.
2. Check the electrode. The following errors can occur with the electrode:
(1) Filling solution was not injected into the calcium electrode, or the wrong filling solution was injected.
(2) The calcium electrode is not filled with enough liquid and the internal reference electrode is leakingot enter the solution
(3) The film at the end of the calcium electrode is degummed, the filling solution runs out, or the white film turns yellow or black.
(4) The filling liquid level of the calomel electrode is lower than that of the calomel core.
(5) The liquid filling in the calomel electrode turns yellow and fails.
(6) The calomel electrode is injected with the wrong filling liquid.
3. After the instrument and electrodes inspection, no problem was found, but the error persists. At this time, add about 30mL of local tap water to a 50mL beaker and place the beaker on the top of the instrument.
The instrument is initially not connected to the electrode. Select the mV potentiometer function, press the reset button, then connect the instrument to the electrode and immerse the electrode in tap water. To thisAt this point, the instrument should show a negative value of about -15 ~ -50 mV.
If the numbers differ too much or appear positive. If the electrode is damaged, the electrode should be replaced.
If the number displayed is normal but the error persists, it means that the solution the electrode is entering is wrong and the solution should be prepared again.
Before calibrating the instrument with the “Calibration Solution”, perform the following checks: disconnect the instrument from the electrode, turn off the stirring, press the “zero” button and wait for the zeroing to complete. Immerse the electrode in the calibration solution,
At the calcium dose, the electrode will read positive tens of millivolts in the 6.0% calibration solution. In the 14.0% calibration solution, the displayed value is greater than de by more than 7-10 millivoltsr displayed value of 6.0%.
When measuring cement dosage, the instrument should read positive tens of millivolts when the electrode is in a 3.0% calibrant solution. In the 10.0% calibration solution, the number displayed is 10-15 millivolts greater than the 3.0% number displayed.
For calcium oxide levels, the electrode should read positive tens of millivolts in the 20% calibration solution. In the 80% calibration solution, the number displayed is 15-20 millivolts greater than the 20% reading.
The following errors are common among users:
1. Phenomenon: The electrode is adjusted in the mV potentiometer in the Calibration solution 1 and the displayed value is greater than positive tenths of millivolts, or 1 is displayed or a negative value appears
Reason: 1. The calcium electrode is degummed or damaged. 2. The calomel battery is damaged. 3. The filling liquid in the elecrode was added incorrectly. 4. The liquid level of the mercury electrode drops.
Actions: Cause 3 and 4 Add filling liquid. Reason 1, 2 Replace the electrode
2. Phenomenon: After calibration, the instrument displays the value of solid calibration solution 1 or calibration solution 2
Reason: Cannot input the instrument's input head error signal.
Measures: The instrument's internal input interface is disconnected, the case is opened, and the disconnected wire is welded.
3. Phenomenon: The instrument display is unstable or drifts greatly during the measurement and calibration process
Reason: 1. The humidity is too high. 2. The instrument is wet. 3. Aging of the electrode.
Actions: Causes 1 and 2 Dry the input head with a hair dryer or open the top cover of the instrument and use a hair dryer to remove moisturereceive. Reason 3 Replace the electrodes.