Overview - J.P. SELECTA PRO-NITRO A Instruction Manual

INSTRUCTION MANUAL
The digital dosifier builds components
from Lee Company U.S.A. (www.
TheLeeCo.com) who pioneered the
miniature fluid control components.
J
.P. SELECTA s.a.u.
CODE 80189 REV E

3 Overview

The PRO-NITRO "A" is a steam distillation unit that includes a colorimetric titra-
tion unit, designed, mainly for organic nitrogen determination according to direct
Kjeldahl method.
This highest automation degree assures more reliable and robust results.
It is very easy to use but its operation must be perfectly known in order to get
good results and avoid losing valuable samples.
Before starting to analyse valuable samples, do some training sessions running the
operations related on the chapter 8, until the operator will be familiar with the unit.
Also the situations when the collector could be contaminated with not neutralized
rests must be understood to avoid wrong results.
Please, start identifying the name of the analyser components:
The steam generator
Generates steam from the water reservoir placed at the top of the unit.
The steam generator includes two safety devices: Safety thermostat: which cuts
the electrical power to the heater when overtemperature is detected on the steam
generator (probably for poor level of water), and the: Pressure switch: which
cuts the electrical power to the heater when there is an overpressure on the steam
generator.
Also includes a capacitive probe to keep a constant level of water in the steam
generator.
The distillation circuit
It is made, mainly, by two glassware parts: The splash protector: its special
design avoids that NaOH splash reaches the cooler glassware, and the cooler: it
condensates the steams that are leaking from the sample. This glassware is cooled
by a water circuit that comes from an external tap. An internal valve opens and
closes this circuit automatically.
NaOH and ammonia fixative solution addition system
Composed by a properly specified pumps to dispense NaOH directly to sample tube
when distillation is running and fixative solution (Boric acid with mix of indicators)
directly to collector before the distillation.
Emptying systems
It consists in some pumps and valves to empty the sample tube and the collector
once the analysis is finished.
Colorimetric automatic titration unit
It performs the titration at the same time that the distilled is obtained.
It has two basic components: The digital dispenser: which dispenses the titra-
tion reagent (usually HCl 0.25N) in volumes of 10 and 50 microlitre, and the color-
imeter which consists in a LED light source and a photodiode.
Software for recording and reporting preparation
PRO-NITRO «A» includes a RS-232 serial output to send data to a printer or to a
computer. This last option allows storing results on the computer and preparing a
report from the batch analysed, according GLP practices.
Computer must have WINDOWS 95 or higher version installed on the PC.
Autovía A-2 Km 585.1 Abrera 08630 (Barcelona) España
e-mail: selecta@jpselecta.es - website: http://www.jpselecta.es
12/2020 Page: 40
Tel 34 937 700 877 Fax 34 937 702 362