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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, there will be errors in the measurement due to various reasons The calibration device. Here you will findan introduction to the inspection steps after a fault has occurred and to determine the possible fault location.
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 the instrument is turned on, a non-zero voltage value is displayed. Press the reset button, after clearing, the zero point will no longer drift, indicating the instrument is normal.
2. Check the electrode. The following errors may occur on the electrode:
(1) The calcium electrode is not injected the inner filling solution; or the wrong internal fill fluid will be injected.
(2) The calcium electrode is not filled with enough liquid and the internal reference elelectrode does not penetrate the solution
(3) The film At the end, 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. No problem was found after the instrument and electrode check, but the error persists. At this time, add about 30 mL of local tap water to a 50 mL 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 leadwater. At this point, the instrument should show a negative reading of about -15~-50mV.
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 penetrates 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 measurement to finish zeroing. 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 morethan 7-10 millivolts greater than the 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 error phenomena are common among users:
1st phenomenon: the electrode is in the mV potentiometer in the calibration solution 1 position , the reading is greater than positive tenths of a millivolt or 1 or a negative value
Reasons: 1. The calcium electrode is degummed or damaged. 2. The calomel battery is damaged. 3. The fill liquidin the electrode was incorrectly added. 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: The error signal of the input head of the instrument cannot be input.
Measures: The internal input interface of the instrument 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 cleanto get moisture. Reason 3 Replace the electrodes.
