Temperature and Humidity Measurement System
Overview
A dedicated system is developed to monitor the:
- Temperature of the BGV gas injection and window chambers
- Temeprature and Dew point inside the detector tent, and inside the cooling manifold
The measurements are stored in the LHC Logging Database.
Initial functional requirements and progress updates can be found in
this document.
Update May 2015: System overview after the addition of the humidity sensors.
Sensors
Temperature sensor
- 4-wire PT100 sensor from Radiospares, see specification sheet
- Complies to norm IEC 751, which is used in the PLC to convert resistance to temperature
Humidity sensor
- QuantaDat/nSens from Novasina, see webpage
- Procurement with the help of Francisco Josa (EN-CV)
- Consists of a electrolytic-resistive probe and a transmitter (for details, see the documents in the webpage above)
- The sensor provides measurement of T and RH. The dew point is calculated by the transmitter.
- The transmitter has 4 analogue outputs (can choose between T, RH, Dew point, ...; can choose the measurement range). In addition it has 2 relay switches which can be configured to provide an electric signal when a threshold is crossed (e.g. interlock for the cooling chiller)
- The transmitter is not qualified for radiation environment and will be installed in the BGV racks (possibly inside the THMS PLC crate)
THMS PLC
A PLC system is developed by Raphael Schlecht (TE-ABT-EC) to:
- Acuquire the signals from the temperature and humidity sensors
- Convert I/U to T (physical or dew point)
- Provide the measurements to a FESA server
Documentation by Raphael:
|
|
|
FESA
A FESA class was developed for the BGV THMS PLC. Thanks to Marco Pimentel (TE-ABT-EC)! Currently the only functionality is to export the temperature and dew point measurements to Timber (no hardware control).
- FESA Class name:
BGV_THMS
- FESA Device name:
BGVDEMO.THMS.B2
- FESA Server:
?
(currently running on a TE-ABT computer)
The existing FESA classes can be explored with the "FESA3 Launcher" application. (how to launch it?)
Timber variables
In the Timber hierarchy, all variables related to the BGV Demonstrator are located in:
LHC -> Beam Instrumentation -> Beam Profile -> BGV Demonstrator
The temperature readings are of type integer. The Timber logging is made whenever there is a change >= 1 °C. In addition, the values are logged every hour (even if there is no change).
The prefix
BGVDA.A7L4.B2 is used for all BGV Demonstrator variables (see comment below).
Currently the following variables are logged:
PT100 probes
Timber variable name |
Name in BGV PLC |
Measured property |
BGVDA.A7L4.B2:TEMP_CHM_WIN_AL |
Temp_Gas_1 |
T of Window chamber flange, Aluminium |
BGVDA.A7L4.B2:TEMP_CHM_WIN_ST |
Temp_Gas_2 |
T of gas injection chamber flange next to Window, Steel |
BGVDA.A7L4.B2:TEMP_CHM_CONE |
Temp_Gas_3 |
T of gas injection chamber, near the center/cone part |
BGVDA.A7L4.B2:TEMP_DET_FTI |
Temp_Tent |
T inside the tent, near the Far-Top-Internal detector module |
Humidity probes (Novasina)
Timber variable name |
Name in BGV PLC |
Measured property |
BGVDA.A7L4.B2:NOVASINA_TEMP_MANIFOLD |
Sensor_1 |
Humidity sensor - Temperature in the Cooling Manifold |
BGVDA.A7L4.B2:NOVASINA_DEWP_MANIFOLD |
Sensor_1 |
Humidity sensor - Dew point in the Cooling Manifold |
BGVDA.A7L4.B2:NOVASINA_TEMP_TENT |
Sensor_2 |
Humidity sensor - Temperature in the Tent |
BGVDA.A7L4.B2:NOVASINA_DEWP_TENT |
Sensor_2 |
Humidity sensor - Dew point in the Tent |
Comment about the name BGVDA.A7L4.B2
:
This name follows the standard Timber variable naming conventions used in the LHC. It is interpreted as follows:
- BGVDA is a name used for the mechanical drawings related to the BGV Detector, model A
- A7L4 is a bit more tricky. It could be interpreted as a vacuum sector, but this is not correct: the BGV Demonstrator is located in vacuum sector B7L4. Names like X7L4 are used in the LHC layout database to name subsystems / devices. The letter X is replaced by a letter A, B, C, ... depending on the location of the device with respect to the IP
- Therefore, BGVDA.A7L4.B2 should be interpreted like: BGV detector system, subsystem located closest to the IP, measuring Beam 2
- Although this prefix is not so useful for the people familiar with the BGV, it is a meaningful reference to the system and its location
Installation photos
Position of the THMS Junction box (connect PT100 sensors to the multiwire long cables) Slots for the PT100 probes on the BGV chambers More BGV installation photos can be found here |
|
|
THMS PLC crate in rack BY12 (occupies U3 to U8 inclusive) More rack photos can be found here |
|