Sensit STHC 102 User manual

SENSIT s.r.o.
Školní 2610, 756 61 Rožnov pod Radhoštěm, Company ID 64087484, VAT ID CZ64087484, telephone: [phone], Fax: [phone]
The company is registered in the Commercial Register administered by the Regional Court in Ostrava, Section C, Entry 13728, se[email protected]z, www.sensit.cz
8500.2
06.17
Replaces
8500.1
USER MANUAL
STHC 102 - COMBINED TEMPERATURE,
RELATIVE HUMIDITY AND CO2 SENSORS
Combined Temperature, Relative Humidity and CO2 Sensors in spaces
protected against the ingress of water, designed for use in railway vehicle
applications

Legal regulations and standards:
Electrical connection of the sensor can be performed only by a person qualified according to Sec. 5 of Decree No. 50/1978
Coll. and closely familiarised with this User Manual.
The User Manual is a part of the product and should be kept during the whole lifetime of the product.
The User Manual should be passed to any subsequent holder or user of the product.
When disposing the product, it is necessary to observe Act No. 185/2001 Coll. on waste as amended and the implementing
Decree No. 352/2005 Coll., on the disposal of electrical equipment and waste of electrical equipment, as amended. In the
European Union, it is necessary to observe the Directive of the European Parliament and Council 2012/19/EU, on waste of
electrical and electronic equipment - WEEE.
All production passes through the final metrological inspection –comparison with standards or working instruments –is
carried out for all the products. Continuity of the standards and working measuring instruments is ensured within the
meaning of the Section 5 of Act No. 505/1990, on metrology. The manufacturer offers a possibility to supply the sensors
calibrated in SENSIT s.r.o.’s laboratory (according to requirements of the EN ISO/IEC 17025 standard) or in an accredited
laboratory.
The sensors are delivered in packages guaranteeing resistance to mechanical impacts and complying with the
requirements of Act No. 477/2001 Coll., on packaging, as amended, which is in conformity with the Directive of the
European Parliament and Council 94/62/EC, on packaging and packaging waste, as amended.
Use of the sensor:
These combined sensors are designed to measure the carbon dioxide concentration, temperature and relative humidity
of air in spaces protected against water. The sensor can be used for any control systems compatible with the MODBUS
RTU communication protocol; communication takes place through the RS 485 bus. The working ranges of individual
sensors are specified in the table of technical parameters. The sensors meet ingress protection IP 30 according to
EN 60 529. Suitable design and high-quality material ensure that the sensors do not feel disturbing even in the interiors with
high aesthetic requirements. The sensors are designed to be operated in a chemically non-aggressive environment, the use
must be chosen with regard to the temperature and chemical resistance of the sensor head, including electronics.
Recommendation for sensor use and positioning:
The sensor is suitable for the measurement of temperature, humidity and concentration of carbon dioxide (schools,
theatres, lecture halls...), offices, interiors of residential houses, rail vehicles or even production floors with variable
occupancy by persons.
Installation is recommended on an inner wall at the height of 1.5 m, in areas of movement of persons, at places not
exposed to direct sunlight and not influenced by heat from walls, heating radiators or lighting.
We recommend performing the first measurable value reading 0.5 to 1.5 hours after the sensor connection to the
supply voltage, when temperature conditions in the box have stabilized.
Operating conditions:
temperature round the sensor: 0 to 45 °C - With guaranteed accuracy of CO2 sensor
-30 to 70 °C - Without guaranteed accuracy of CO2 sensor
relative humidity: 0 to 85% (Non-condensing moisture) - With guaranteed accuracy of CO2 sensor
0 to 95% (Non-condensing moisture) - Without guaranteed accuracy of CO2 sensor
atmospheric pressure: 87 to 106 kPa
Warnings and restrictions:
The sensor must not be used for temperature measurement in areas:
where the specified technical parameters and operating conditions are not adhered to
where there is a risk of a mechanical impact on the sensor or a potentially explosive atmosphere
with a chemically aggressive environment
where the sensor could be exposed to high air humidity with the possibility of condensation of inundation
The sensor should not be used for temperature measurement in areas:
where it could be exposed to direct heat radiation (lights, heating radiators, etc.) or insolation
where free access of air is not ensured and where free air flow is restricted (spaces under windows, recesses in walls,
spaces under roof verges, balconies, etc.)
where measurement errors could occur due to warm air from inner spaces (spaces above windows, doors and ventilation
apertures)
it is not advisable to install the sensor on facade sections with high thermal capacity, on walls in the vicinity of, for example,
a chimney
where the supply cable could be routed in parallel with power distribution lines (risk of induction of interfering signals and
thus influencing the measurement results); a safe distance from the distribution network in parallel cabling can be up to
0.5 m, depending on the nature of interfering fields.
A failure to comply with these recommendations will negatively affect the measurement accuracy, reliability, and the service
life of the temperature sensor.

Description of the sensor:
The sensor consists of a plastic head containing sensors of temperature, relative air humidity and CO2concentration
and a terminal block for the connection of the supply cable. The plastic head consists of a base and a perforated cover,
providing access of air to individual sensors. The supply cable is attached to the terminal board through the opening in
the base. The base material of the sensor head is LEXAN™ Resin EXL5689.
Temperature and relative humidity are measured by an internal sensor whose signal is processed in a microprocessor
and converted to an output signal. The CO2value is measured by an NDIR module whose digital signal is also
converted to an output signal.
“CO2” autocalibration – the function provides setting of the minimum CO2value corresponding to the outdoor
concentration level. The autocalibration process assumes that, during a measured period of approx. 8.5 days (without
interruption of the power supply), there will be at least one drop of CO2concentration to 400 ppm corresponding to the
outdoor concentration. In permanently occupied and non-ventilated rooms, however, this function will not work and must
be deactivated – register “settings – bit 0”.
Installation of the sensor:
1. Before connecting the supply cable, detach the perforated cover from the plastic head base. Removing the cover
requires a working tool – a thin screwdriver, a metal tube with a tip diameter of 2 to 2.5 mm and a minimum length of
30 mm. During this operation, take care to prevent mechanical damage of the sensing element – refer to
“Cover removal”.
use the left hand to firmly grasp the base (bottom of the box)
insert the box opening tool as deep as possible into the left opening No. 1 in the direction of the arrow A (when
inserted, the tool is tilted at an angle parallel to the side wall of the box)
then, press the tool in the direction of the arrow B to dish the box cover and release it from its lock while slightly
lifting the cover from the base.
repeat the same procedure on the other side of the box, through the opening No. 2
when the cover has been unlocked on both sides, it can easily be separated from the base
Warning:
It is not advisable to open the box by pushing the side locks inwards – as it can lead to the locks breaking off
and losing their function of locking the base-cover connection. It can also result in mechanical damage to the
outer surface of the box.
Cover disassembly: Drawing of the base:
2. Put the drilling template on the expected location of the sensor or at a location where the supply cable is lead out
from a wall and mark the position of drilling points with a diameter of 3 mm for the installation of the base and, if
necessary, also a drilling point with a diameter of 9 mm for the power cable. The recommended working position
of the sensor is defined in such a way that the round section of the box is oriented downwards – refer to
“Base drawing”.
Place for grasping the base
Hole for the
communication line and
power supply cable 9
Sensor
T & RH sensors
Hole for
screw 3
Hole for
screw 3
CO2sensor
position
1
2

3. At the designated drilling points for the installation of the base, drill the holes for dowels or cut M3 threads for
mounting screws or bolts.
4. Insert the power cable through the 9mm hole, attach the base to the surface and fix it using two screws or bolts. The
length of the mounting bolts or screws for fastening must be chosen with respect to the thickness of the plastic head
base.
5. Connect the power cable to the terminals according to the “Wiring diagram”, position the perforated cover onto the
base and lock it by clicking in.
6. After installing and connecting to the electrical measuring equipment, the sensor is ready for use. The sensor does
not require any special servicing or maintenance.
Wiring diagram:
GND, PWR –Power supply Ucc
K+, K- –communication line
BUS END –RS 485 line END
Technical parameters:
* The temperature and relative humidity stabilization period is 0.5 to 1.5 hours after connection to a power supply,
depending on the conditions around the sensor (airflow, set correction amount, communication frequency, etc.).
Guaranteed accuracy is achieved within 0.5 hours after power connection.
** For a short period, the sensor may be exposed to temperatures ranging from -40 to 80 °C.
Temperature measurement range **
0 to 45 °C With guaranteed accuracy of CO2 sensor
-30 to 70 °C Without guaranteed accuracy of CO2 sensor
Temperature measurement accuracy *
± 0,5 °C in range 0 to 65°C
± 0,7 °C in range 65 to 70°C
± 1,1 °C in range -30 to 0°C
Relative humidity measurement range
0 to 85 % With guaranteed accuracy of CO2 sensor
0 to 95 % Without guaranteed accuracy of CO2 sensor
Relative humidity measurement accuracy *
± 3 % in range 10 to 90 %
± 4,5 % in range 0 to 10 % and 90 to 95 %
CO2 measuring range
400 to 5000 ppm
CO2 measuring accuracy
± 200 ppm *
Time response CO2 (90%)
90 s
Output signal
RS 485 / MODBUS RTU
Supply voltage U
15 to 30 VDC
Rated supply voltage U
24 VDC
Consumption
maximum: 500 mW
typical: 250 mW
Ingress protection
IP 30 according EN 60 529
Recommended wire cross section
cross section: 0,14 to mm2
outer diameter: max. 6 mm
Dielectric strength according EN 50155
1,5 kVDC for time 1 minute
Shock and vibration according EN 61373
category 1, class B
Dimension of the head
71,9 x 59 x 27
Material of the head
LEXAN™ RESIN EXL5689
Weight
min 35 g
K- K+
BUS END
1 2
GND
PWR
SWITCH
INIT
RS 485
-
+
U

Safety:
Within the type tests, the product safety and the technical parameters have been assessed according to the following
standards and technical regulations, as amended:
EN 60950-1, EN 60529, EN 60770-1
MODBUS protocol description:(complete description of the protocol – www.modbus.org)
0x01 Read Coil Status bit reading
0x03 Read Holding Registers word reading (16 bits)
0x0F Write Multiple Coils bit writing
0x10 Write Multiple Registers word writing
note: – 50 registers can be read or written in one query
– default values are stated in brackets for the address type
Register Description:
Name
Address
Type
Description
Note
module ID
1 LSB
R
module identification
0xF204
1 MSB
firmware
2 LSB
R
firmware version
2 MSB
status LSB
3 LSB
R, W RAM
low byte module status
EEPROM initialization - after
bit 0 – enables writing in EEPROM
power connection, SWITCH
bit 1 – enables SW reset
INIT must be short-circuited
bit 4 – EEPROM initialization
– when writing bit 4 to”1”,
SWITCH must be disconnected
(indicated by bit 2 in MSB);
SW reset can be performed by
writing the register SW reset
(adr. 1002)
status MSB
3 MSB
R, RAM
high byte module status
bit 0 – 0 normal mode
– 1 init mode
bit 1 – 1 when the next data is written in the
memory stored in EEPROM, all data
is written in EEPROM
– 0 when the next data is written,
received data is written only in RAM
bit 2 – 1 – EEPROM initialized
bit 3 – reserve
bit 4 – 0
bit 5 – enables SW reset
bit 6 – 0
bit 7 – 1
ADDRESS
4 LSB
R,W EEPROM
module address
!! ATTENTION !! the change
(0x01)
will take effect only after
the device is restarted
(register setting will be executed
immediately, address change
after the restart)
BAUD RATE
4 MSB
R,W EEPROM
communication without parity
!! ATTENTION !! the change
(9600 bps,
10 dec … 1200 bps
will take effect only after
13dec)
11 dec … 2400 bps
the device is restarted
12 dec … 4800 bps
(register setting will be executed
13 dec … 9600 bps
immediately, speed change
14 dec … 19200 bps
after the restart)
15 dec … 38400 bps
16 dec … 57600 bps
17 dec … 115 200bps

Serial port
5 LSB
R,W EEPROM
setting of serial link parameters
!! ATTENTION !! the change
will take effect only after the
device is restarted
settings
(without parity,
bit 0–1 parity 00 – no parity
one stop
01 – even
bit, 0x00)
10 – odd
bit 2 number of stop bits 0 – one
1 – two
5 MSB
reserve
EEPROM
6 LSB
R, EEPROM
number of writes in EEPROM
EEPROM initialization doesn´t
zero this register, doesn´t rotate
writes
6 MSB
7 LSB
reserve
7 MSB
8 LSB
reserve
8 MSB
Actual
9 LSB
R, RAM
current measured temperature in 0.01 °C
with sensor correction (see temp sensor
corr)
16bit signed value
Temp
9 MSB
Actual
10 LSB
R, RAM
current measured humidity in 0.01 % with
sensor correction (see rh sensor corr)
16bit signed value
RH
10 MSB
Actual
11 LSB
current CO2value in ppm 0.01 % with
sensor correction (see CO2sensor corr)
In ppm
CO2 ppm
11 MSB
12 LSB
reserve
12 MSB
13 LSB
reserve
13 MSB
14 LSB
reserve
14 MSB
Temp sensor
15 LSB
R,W EEPROM
temperature sensor correction in 0.01 °C
16bit signed value
corr
15 MSB
(-2,9 °C)
(self-heating effect of electronics)
RH sensor
16 LSB
R,W EEPROM
relative humidity sensor correction
16bit signed value
corr
16 MSB
(7,6 %)
in 0.01 %
CO2 sensor
17 LSB
R,W EEPROM
CO2sensor correction (elimination of the
influence of altitudes, calibration,...
With the CO2sensor
autocalibration activated, this
register is set automatically
every 8.5 days with
uninterrupted power supply.
corr
17 MSB
(0 ppm,
0x0000)
settings
18 LSB
R,W EEPROM
configuration register for autocalibration
18 MSB
(enabled,
bit 0 – enables CO2autocalibration
Powered on
bit 1 – CO2power supply 0 – off
0x0003)
1 – on
19 LSB
19 MSB
20 LSB
20 MSB
reserve
uptime
1000 LSB
1000 MSB
1001 LSB
1002 MSB
R
Uptime ( s )
SW reset
1002 LSB
1002 MSB
R,W, RAM
Writing of a non-zero value performs a SW
reset, if previously enabled.
See Status LSB bit 1
Serial num.
1003 LSB
1003 MSB
1004 LSB
1004 MSB
R, W OTP
Module serial number, writing only at
module production.

Default Parameters:
Baud Rate 9600 bps, 13 dec Stop Bits 1 Temp sensor corr -2,9 °C
Data Bits 8 Module Address 0x01 RH sensor corr 7,6 %
Parity None Module ID 0xF204 CO2 sensor corr ---
Settings Autocalibration enabled, CO2 power enabled
Declaration of Conformity
SENSIT s.r.o. provides the product with the EU Declaration of Conformity issued according to Act No. 90/2016 Coll.
and Act No. 22/1997 Coll., as subsequently amended. The product is in accordance with the following directives:
European Parliament and Council Directive 2011/65/EU of 8 June 2011 on the restriction of the use of certain
hazardous substances in electrical and electronic equipment
European Parliament and Council Directive 2014/30/EU of 26 February 2014 on the harmonisation of the laws of the
Member States relating to electromagnetic compatibility
Storage, delivery, complaints and repairs:
The sensors can be stored at place with ambient temperature 5 to 40 °C and relative humidity 5 to 85%
Each delivery contains the following unless otherwise agreed by the customer sensor according to purchase order,
Instruction Manual, including Guarantee Certificate and Delivery Note
Guarantee and after-guarantee repairs of sensors are ensured by the manufacturer. The product must be delivered
including a copy of the Guarantee Certificate, duly packed and fit to shipment so as not to get damaged during
transportation.
GUARANTEE CERTIFICATE
The product is covered by guarantee for 24 months from the date of purchase.
In this period, the manufacturer will remove all material or manufacturing defects arisen demonstrably during the
applicable warranty period. The manufacturer is liable for the technical and operational parameters of the product given
in the user manual. Any identified defects will be claimed by the buyer without undue delay after their identification or, as
appropriate, after the buyer was able to identify them during his routine care. A completed Warranty Certificate with a
brief description of the defect plus the product must be submitted with the claim.
Warranty does not cover a product:
That was damaged during transport and inappropriate storage, improper commissioning and/or that has been used for
a purpose other than specified
That has been used in an improper manner, inconsistent with the user manual and/or generally applicable technical
standards or safety regulations
That is worn or damaged as a result of normal use of the product, without loss of its operational characteristics and
guaranteed technical parameters
Into which unskilled intervention, unauthorised structural or other changes (reprogramming, resetting of set
parameters, etc.) have been made
That is mechanically damaged, e.g. by fall, being hit by a hard object, cleaning with unsuitable agents, power cord
tearing/breaking, breaking or other damage of individual product parts
That has been exposed to adverse external influence, e.g. object intrusion, wrong supply voltage, influence of
chemical processes, electrical surge (obviously burnt components or printed circuits), dusty, dirty, aggressive or
otherwise unsuitable environment, except normal variation
That has been damaged by an incidental or natural disaster or as a result of natural or external phenomena, such as
storm, fire, water, excessive heat
That is claimed without the Warranty Certificate or nameplate.
Rights and obligations regarding the rights arising from defective performance will be governed by the applicable
legislations and the applicable Business Terms and Conditions of SENSIT s.r.o. and this Warranty Certificate.
Date of sale confirmation:
Serial number: