Detection method:ISE (Ion Selective Electrode)
Test indicators:the alkali content of concrete and raw materials, means the equivalent content of sodium oxide Na2O (%)
Product Model: NJAL-H
Product Application:
Concrete materials contain alkali (potassium ion, sodium ion).When the concrete is in the sufficient moisture environment after a period of time, the concrete bases alkali (potassium ion, sodium ion) will react with the active silicon in the thickness aggregate. The reaction will cause the expansion of the structure and cracking, means the alkali-aggregate reaction. As the alkali-aggregate reaction will cause harmful effects to concrete structures, both domestic and foreign departments take great attention to concrete alkali content limits.
According to “Standard for Maximum Alkali Content in Concrete” CECS *3:*3, “Standard for Durability Assessment of Concrete Structures” CECS **0:***7 and some other relevant standards, the concrete alkali content refers to the equivalent oxidation sodium content in the concrete, by kg/m3. The alkali content of the concrete raw material refers to the equivalent oxidation sodium content in the concrete raw materials, by weight percentage (%). And the oxidation sodium content is equivalent to the sum of the oxidation potassium plus the oxidation sodium times 0.**8, namely "the equivalent oxidation sodium content= Na2O + 0.**8 * K2O".

 The apparatus adopts Ion Selective Electrode method (ISE), and it uses the United States imported composite potassium Ion Electrode and composite sodium ions Electrode to rapidly test the alkali content (%) of the concrete (including fresh concrete, wet concrete, hard concrete powdery sample, etc) and the concrete raw materials (including the cement, chemical additive, admixtures, etc.) at room temperature
Executive Standard
1. ‘Standard for Maximum Alkali Content in Concrete’ CECS *3: *3
2. ‘Standard for Durability Assessment of Concrete Structures’ CECS **0:***7

1. *0minutes test cycle to rapidly test the concrete alkali content

2. Specific anti-ion interference agent, strengthen ion concentration and remove all kinds of metal interference effect in the same time

3. High precision potassium, sodium ions composite electrode, stable performance

4. Large LCD screen straight display, hand-held printer for instant printing, operation is reasonable

5. Unique self-diagnosis function, original PC analysis software

6. Great data storage capacity, can store **0 test data

7. Data record continuous, safe and reliable

Test object:fresh concrete, wet concrete and concrete raw material

Detection principle:
NJAL-H rapid concrete alkali tester adopts ion selective electrode method (ISE method) rapidly to test the alkali content of the water-soluble matter, such as concrete, gravel, and additive.
The concrete or other samples should be pretreated before usage. Put the two prior activated and calibrated electrode into the mixture according to the instructions, one of the electrode tests the sodium ion content, the other one tests the potassium ion content. The instrument can turn the tested voltage data (mv) into Na2O and K2O content (%) through the calibration curve. After filling the result to the host calculation formula, it will automatically get the Na2O percentage (%) of the concrete alkali content. After the electrode activation, each experiment process will need only *0 minutes.

Power voltage: AC **0V

Working voltage: DC 3.6V

Test precision: =<*0%

Printer working voltage: DC 5V

Data storage capacity: **0

Pc communication parameters: ***0 baud rate

Acquisition cycle: =<3min

Standby time: >*4 hr

Weight: **0g

LCD SCREEN dimension: **8***8

Test step:
1) Activate electrode
2) Weight and pretreat the samples according to the instructions
3) Calibrate electrode and test the sample solution
4) display measured data

Test results:
1) Concrete alkali content percentage (%)
2) Concrete oxidation sodium percentage(%)
3) Concrete oxidation potassium percentage(%

Measuring range: 0.**1% ~ *0.**0%

Measuring precision: +/**0%

Operating temperature: 0centigrade ~ *5 centigrade

Resolution: 0.**1.

System Configuration
1.NJAL-H rapid concrete alkali tester
2.Composite sodium ion Electrode
3.Composite potassium ion Electrode
4.Calibrated solution, ionic strength adjustor
5.Charger
6.Hand-held micro-printer

7. PC computer software