LABBOX KJD20, User Manual, Page: 6 / 21

6
 + + ⎯ ⎯ ⎯ ⎯ ⎯ ⎯ → ⎯ +
3 2 4 2
steam e temperatur - high
4 2 4
2 2 2 ) ( NH O H SO Na NaOH SO NH
O H O B NH BO H NH
2 7 4 2 4 3 3 3
5 ) ( 4 2
+ = +
2. Theory
According to the Kjeldahl theory, there are three processes including digestion, distillation and titration
in the test. The Kjeldahl Distillation Unit is able to execute the distillation process automatically.
The chemical reactions listed below occur after a sample has been completely digested.
[1]
[2]
Via the condensing pipe, the ammonia gas and steam released during the reaction are condensed and
collected into the receiving flask where the boric acid (with mixed indicator) is added.
III. Specifications
1. Technical Specifications
a. Measurable amount of the sample: solid ≤ 5 g; liquid ≤ 20 mL
b. Measurement range: 0.1 mg ～ 240 mg of nitrogen
c. Time for measurement: 3~6 min
d. Recovery rate: ≥ 99.5 %
e. Relative Standard Deviation (RSD): ≤ 0.5 %
2. Working Conditions
a. Rated power: 1300W
b. Input voltage: AC 220 ±10% V (50/60±1) Hz; reliable ground wire is needed.
c. Cooling water pressure: > 0.15 MPa
d. Cooling water temperature: ≤ 20
℃
e. Temperature of environment: 10
℃
～ 35
℃
Working Humidity: 35
℃
and max. relative humidity 67 %; 31
℃
and max. relative humidity 80 %.