JUMO 201040 User manual

Ammonia-sensitive sensor for measuring
ammonia in aqueous solutions
Type 201040
B 201040.0
Operating instructions
V1.00/EN/00451666

1 Notes ..................................................................................... 4
2 Description ........................................................................... 5
2.1 Areas of application ............................................................................ 5
2.2 Function .............................................................................................. 5
2.3 Operating conditions .......................................................................... 5
2.4 Coolant monitoring ............................................................................. 6
3 Technical data ...................................................................... 7
4 Operating range ................................................................... 8
4.1 Output signal ...................................................................................... 9
4.2 Design ............................................................................................... 10
5 Mounting ............................................................................. 11
5.1 Dimensions ....................................................................................... 11
6 Electrical connection ......................................................... 12
7 Startup ................................................................................ 12
7.1 Taking the temperature dependence of the ammonia sensor into
account when using it in combination with JUMO dTRANS pH 02
or JUMO AQUIS 500 pH .................................................................. 13
7.2 Calibrating the ammonia sensor ....................................................... 14
8 Maintenance ....................................................................... 16
8.1 Refilling/replacing the electrolyte ..................................................... 17
8.2 Storing the sensor in the storage container ..................................... 19
8.3 Removing the electrode from the storage container ........................ 19
9 Accessories ........................................................................ 20
9.1 Quick-change fitting for ammonia sensor ....................................... 20
9.1.1 Replacing the PTFE washer in the quick-change fitting .................... 22
9.2 Maintenance kits .............................................................................. 24
10 Possible errors ................................................................... 24

4
1 Notes
Note:
All necessary settings are described in this operating
manual. If any difficulties should nevertheless arise
during startup, please do not tamper with the sensor
in any way. By doing so, you could endanger your
rights under the instrument warranty! Please contact
the nearest subsidiary or the head office in such a
case.
Please read this operating manual before placing the
instrument in service. Keep the operating manual in a
place which is accessible to all users at all times.
For technical questions
Service hotline:
Phone: [phone] or
[phone]
Fax: [phone] or
[phone]
E-mail: [email protected]
More information can be found in JUMO white paper
631, "Information on measuring ammonia in water".

5
2 Description
2.1 Areas of application
Refrigerating plants (such as indoor ice rinks, cold stores, etc.),
frequently use ammonia as the refrigerant. Ammonia (NH3) is a
toxic, pungent-smelling and colorless gas. These refrigerating
plants are monitored for escaping ammonia (leakage).
To do this, tubes and system parts filled with water are monitored to
determine whether ammonia (NH3) has penetrated (dissolved in the
water). The ammonia-sensitive sensor type 201040 described here
is suitable for this purpose.
2.2 Function
A gas-permeable, hydrophobic PTFE film makes the connection
between the process medium and the sensor electrolyte. A
hydrogen ion-selective electrode is immersed in the electrolyte.
Ammonia escaping through the PTFE film changes the pH value of
the electrolyte. The NH3concentration in the process medium can
be measured in this manner. The electrolyte contains ammonium
(NH4+) ions, with which the sample gas is in chemical equilibrium.
2.3 Operating conditions
The concept of an ammonia leakage monitoring system must
ensure that the escaping coolant reaches the ammonia-sensitive
sensor type 201040 quickly.
The sensor must be installed in a quick-change fitting part no.
00379538. The porous PTFE washer in this quick-change fitting
must not be clogged! If it is, ammonia leakage will be detected too
late or not at all. If necessary the customer should install a filter
upstream from the sensor.
The flow rate of the monitoring circuit must be checked at regular
intervals! A few drops over several hours is sufficient. If the flow rate
Attention:
The ammonia-sensitive sensor type 201040
described here is not suitable for detecting ammonia
in ambient air!