Download XEN-5310

XEN-5310
TCG (XEN-TCG3880) with read-out
Preliminary datasheet
Features
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Binary gas composition measurement
Vacuum measurement
Analog (12 bit) & digital output
Measurement with proven Thermal Conductivity
Gauge XEN-TCG3880
Read-out with dedicated ASIC chip for biasing
and measuring the sensor components
Temperature and humidity compensated
Temperature range: -20 ºC to +55 ºC
Humidity range: 0-100% RH, non-condensing
Start-up time: 1 second
T90 sensing and T10 recovery time: 1 second
Operation: 5 V @ 20 mA
Digital output (RS232 @ 3.3 V)
Dual Analog output
Available in modular form with exchangeable
TCG sensor in socket
RS232 to USB converter board available.
XEN-5310 sensor,
approximately real size (58×25 mm)
Applications
 Examples:
- Measurement of helium, CO2, hydrogen concentration.
- Detection of gas dispersion rate in jets and plumes.
Description
The XEN-5310 is an intelligent gas sensor for gas detection, based on the measurement of the
thermal conductivity of the ambient gas. To compensate for the influence of temperature and humidity, these are measured separately and a correction is made for them in the micro-controller.
Each device is factory calibrated, with the option of recalibration by the customer.
Block Diagram
TCGauge
Digital IO
ASIC
Connector
Analog out
Micro-controller
LED indications
Pt100
RH sensor
Voltage regulator
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
copyright Xensor Integration
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 1 of 7
XEN-5310
TCG (XEN-TCG3880) with read-out
Preliminary datasheet
Preliminary Specifications (at 23 ˚C, 101 kPa, 50% RH)
Item
Typical
General
Sensitivity for traces of H2
Sensitivity for traces of He
Sensitivity for traces of CO2
Sensitivity for vacuum
Digital output
Analog output
LED Alarm
Noise
Offset drift
Operating limits
Temperature operating range
Temperature changes
Humidity operating range
Humidity changes
Pressure range
Remarks
-2.1
-1.1
+0.4
-4.7
%/%
%/%
%/%
%/Pa
0.04
0.12
%
%/yr
Signal change for concentration in air
Signal change for concentration in air
Signal change for concentration in air
For low pressures
See list
User specified
User specified
Of signal in air
Of signal in air
ºC
ºC/min
%RH
%RH/min
mbar
mbar
For full accuracy
Maximum rate of change
Non-condensing
Maximum rate of change
Full accuracy
Reduced accuracy
-20 to + 55
<1
0-100
<1
800-1200
200-800
Operation speed
System start up time
T90 response time
T10 recovery time
Data update rate
1
1
1
1
Electrical
Current consumption
Supply voltage
Output signals
Digital
Analog signal: signal change
Analog alarm: code
Storage
Temperature storage limits
Humidity storage limits
Unit
Second
Second
Second
Hz
20
5-8
mA
V
0-3
0-3
V
V
10-40
20-70
copyright Xensor Integration
RS232 @ 3.3 V
User Specified
User Specified
ºC
%RH
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
100 mW @ 5 V
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 2 of 7
TCG (XEN-TCG3880) with read-out
XEN-5310
Preliminary datasheet
Functional description
The XEN-5310 determines the concentration of a specified gas in air. This is done by measuring
the thermal conductivity of the ambient air using a thermal conductivity gauge (TCG), and comparing
this to the factory calibration measurement. To eliminate the influence of temperature and humidity,
these are measured separately, and a compensation is made by the micro-controller. The remaining
difference between the measured and calibrated value of the thermal conductivity is then a measure
of the gas concentration.
Range and poisoning
Since the TCG is not poisoned by an overdose of gas, the operating range is 0-100% for noncorrosive and non-condensing gases. The analog outputs can be specified for their range and
desired alarms. The digital output gives all concentrations, if calibration curves are available for the
user-specified gas.
The capacitive humidity sensor can be sensitive to poisoning by silicone vapors, so these have to
be avoided.
Selectivity
The TCG-based device is non-selective in that it will give an output in the presence of any gas
having a thermal conductivity different than air.
The sensor is especially useful for the measurement of helium and hydrogen, which have thermal
conductivities that are 6x resp. 7x as high as that of air at room temperature.
Most other gases have much lower thermal conductivities than helium, with neon at 2x the thermal
conductivity of air as the highest of the others. So, other gases give much smaller signal changes.
Methane has a thermal conductivity of about 40% higher than that of air, and CO2 (carbon di-oxide)
nearly 40% lower. These gases can still be measured using the XEN-5310. However, CO (carbonmonoxide), for example, has about the same thermal conductivity as air, so this gas is very difficult
to detect with a thermal conductivity measurement.
Safety
Note: the XEN-5310 is not CE approved.
Note: the XEN-5310 is not approved and equipped for hydrogen leak detection in safety applications.
Options
The XEN-5310 has several options, see also the selection Table at the end.
Calibration
First of all the calibration can be chosen. This means that the analog and digital output signals can
be calibrated for the concentration of a specific gas in, for instance, air. The standard options are
helium (in air) and hydrogen (in nitrogen). The digital output signal is always full range, -5% to
105%, with 5% undershoot and overshoot to allow for tiny variations in the zero and gain. The analog output signals can be chosen. Other standard options are a general output and a vacuum output. Custom options are gases such as CO2, CH4, argon and other gases.
Apart from the digital output signal, a number of other signals are available as digital output.
For the analog output, a second output is available for safety alarms. At this time, no specific safety
checks are made in the XEN-5310. This is available as special, custom option.
Data rate
Standard the data or measurement rate of the XEN-5310 is 1 Hz, one measurement per second.
This will allow for safety checks to be made if so desired (no standard safety checks are made in
the XEN-5310).
An increased data rate of 2 Hz still gives all the measurement data, but no safety checks can be
made any more.
The highest data rate available is 4 Hz, every 250 ms measurement data are available. However,
no humidity measurement is made, and no correction is made for changes in humidity. This can
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
copyright Xensor Integration
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 3 of 7
TCG (XEN-TCG3880) with read-out
XEN-5310
Preliminary datasheet
degrade the accuracy of the output signal, especially at higher temperatures, where the absolute
humidity can be increased (at room temperature, the absolute humidity is maximally about 3 kPa
against 100 kPa atmospheric pressure). However, for helium and hydrogen measurements in the
percentage range at room temperature, this is not very critical, and the increase measurement rate
can be very important.
The supply voltage is also not monitored anymore.
Sensor type
Standard the XEN-5310 is equipped with a XEN-TCG3880-P2-W-R sensor. That means, a standard thermal conductivity gauge, with a Pt100 temperature sensor on board (P2), with a roof over
the sensor chip to shield it from flow effects (R), and with a cap having a 5 mm hole, covered by a
screen filter welded to the TO-5 header (W) for mechanical protection and flow shielding.
This sensor has a t90 time constant of 1 s.
For fast measurement applications, in combination with the high data rate, it can be interesting to
mount a special, ultra-fast sensor. This does not have the welded cap, and is made to exchange
gas with the ambient very fast. The code is XEN-TCG3880-P2-RR-U. Extra roofing (RR) is applied
to give this sensor a reduced flow sensitivity. At 1 l/min in a 4.5 mm inner diameter pipe no significant flow effects were found, but a t90 of the order of 50 ms was measured for hydrogen and helium. Of course, at lower flow velocities a somewhat higher time constant may be expected.
Because of the vulnerability of this sensor, this option includes a socket to insert the sensor on the
XEN-5310 board (standard, the sensor is soldered to the board).
Other options
Other options include a housing, and flow adapters. The flow adapter is especially interesting when
using the ultrafast sensor, which is unprotected. This sensor will fit in the flow adapter, which is fastened to the XEN-5310 with screws. The adapter gives a 4.5 mm diameter flow channel, with the
option to screw in M5 flow-circuit parts.
Software
The XEN-5310, if in combination with the XEN-85000 USB read-out board comes with LabView
software to read out digitally. The read-out includes signals such as sensor output voltage, transfer,
heater current and voltage, output signal, supply voltage, humidity and temperature.
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
copyright Xensor Integration
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 4 of 7
TCG (XEN-TCG3880) with read-out
XEN-5310
Preliminary datasheet
Instructions for Use
Proper ventilation
Above all other measures, the user must take care that the sensing element is properly ventilated
so that the gas to be measured can access the sensing element through diffusion into the cap via
the hole in the cap. Blocking this hole, or proper ventilation of the instrument in general will make
the device non-functional, while still it will indicate proper values. This must be avoided at all
times. Although some checks can be made, non-ventilation of the whole instrument cannot be
detected and there is therefore no warning against such a situation.
Condensing and water dropping onto the sensors
Precaution must be taken against condensing of water vapor in the sensor or water drops falling
onto the sensors, as this may lead to (irreversible) malfunctioning. Preferably the sensor is
installed in such a way that the opening of the thermal conductivity gauge is downwards, to avoid
contamination by water drop, dust or other matter falling onto the gauge and the humidity sensor.
However, the sensor will function properly in any orientation.
Humidity sensor influence and care
More specific caution should be taken when subjecting the humidity sensor to extreme values of
temperature and humidity. When subjected to temperatures below zero or humidities around zero,
the humidity sensor may take some time to recover. It is therefore not advised to use the XEN5310 at these extremes and then suddenly expose the XEN-5310 to high temperatures (above
room temperature) and humidities, this can temporarily lead to falsely indicated concentrations.
Exposure to very high humidities over the 90% RH may lead to some drift of the sensor, and thus
to drift of the XEN-5310 at the high end of the temperature range.
In general inaccuracies of the humidity sensor will be more serious at temperatures above room
temperature, since the absolute humidity almost doubles every 10 ºC, while the effect of humidity
is proportional to the absolute humidity (in kPa). At room temperature of around 25 ºC the
maximum water vapor content in air is about 3 kPa or 3%, and this may lead to a signal change
of the order of 0.6%.
At 55 ºC, the upper limit of the XEN-5310, the maximum water vapor pressure is about 15 kPa.
Proper correction for humidity is therefore necessary, in particular for the higher end of the
temperature range.
Flow and sudden changes in the ambient
Sudden temperature shocks and humidity shocks may lead to spurious signals in the sensor
output. Also sudden movement of the sensor and strong air flow directly onto the sensor may lead
to spurious signals. This does not normally lead to an alarm situation, except for extreme shocks.
Periodic calibration
In normal circumstances, a total drift of the sensor offset of well below 2000 ppm per year is
typical, when measuring under identical circumstances (same temperature, humidity and
pressure), and no calibration is required until such time as the deviation becomes significant (i.e.,
5000 ppm signal change when pure air is supplied).
It is advised to periodically check the functioning of the thermal conductivity gauge. In practice,
it will suffice to determine the sensor output in a normal situation where the absence of a deviation
from the normal air composition is established, and where no significant temperature and humidity
changes or gradients are present. This would also be apparent from the indicated signal-level,
which should be stable. In that case a (near-)zero signal change should be indicated. If suddenly
a significant change of more than 2000 ppm typically is observed while the operation
circumstances have not changed, the temperature sensor and humidity sensor should be
checked for proper operation, and possibly a recalibration should be carried out.
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
copyright Xensor Integration
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 5 of 7
XEN-5310
TCG (XEN-TCG3880) with read-out
Preliminary datasheet
Electrical characteristics
The XEN-5310 sensor requires a nominal supply of 5-8 V and about 20 mA at room temperature.
This supply voltage is converted to the internal operating supply of 3.3 V. The minimum and maximum supply voltages are 4 V and 12 V, the sensor will stop operating when a voltage of less than
approximately 3.5 V is supplied. Such low power supply voltages are not recommended, as the
operation of the sensor is no longer complete (for instance, the sensor can no longer display the
analog signal up to 3 V).
A power supply of more than 12 V will lead to increased power consumption, and self-heating of the
PCB.
It is recommended to have the supply voltage close to 5 V, any excess voltage will be converted
into heat dissipation, possibly causing thermal drift of the sensor.
Trouble Shooting
In case of trouble:
 First try to get the sensor to work again by disconnecting and connecting the power supply.
 If the sensor is out of the operating offset range in the absence of gases other than air,
recalibrate if possible.
 If the sensor will still not operate properly then contact the manufacturer:
call +31 15 2578040 or email [email protected].
Physical dimensions and connections
The XEN-5310 is standard supplied with an 8-terminal 2-row micro-fit connector, with on the bottom
row the power supply and the analog output signals. On the top row the RS-232 signal lines and an
additional ground connection are situated.
If so desired, the sensor can also be supplied with a 4-terminal single row connector, omitting the
RS-232 connection.
Furthermore, if so desired a 3-wire connection is possible with only a single analog output, where a
modulation on the analog signal output will be installed instead of on the analog alarm output.
Physical geometry of the PCB, top view and view from connector side:
58.4 mm
9 mm
3.2 mm mounting holes
connector
capacitor
20.3 mm
38.7 mm
TCG
10 mm
25.4 mm
14 mm
Connections of the 2-row 8-pin AMP connector, view from outside of board:
Tx
Gnd Rx
Out1 Gnd Out0 Vdd
Printed Circuit Board thickness 1.6 mm, components on both sides. All components are less than
3 mm high, except for the connector, TCG and buffer capacitance.
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
copyright Xensor Integration
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 6 of 7
TCG (XEN-TCG3880) with read-out
XEN-5310
Preliminary datasheet
Order Information and Accessories
Standard version
 The order code for the XEN-5310 sensor with standard options: XEN-5310-He-2Hz-100%.
 Cable pack 1 is included: cable connector + separate contacts not assembled.
Options for the XEN-5310 sensor
Option
Select
Code
Content
Availability
Calibration
He
H2
General
Vacuum
Custom
He
H2
Gen
Vac
Custom
Digital output for helium in Air
Digital output for hydrogen in nitrogen
Digital output for transfer deviation
Digital output for nitrogen pressure
Digital output for other gases (CO2, CH4, etc)
Standard
Standard
Standard
Standard
On request
Data Rate
1 Hz
2 Hz
4 Hz
1Hz
2Hz
4Hz
Full functionality
No safety
No humidity correction, no safety
Standard
Standard
Standard
Sensor Type
Standard
Ultrafast
U
Standard (1 s) sensor, soldered
Exposed, ultrafast (50 ms) sensor and socket
Standard
On request
Analog output
Full range
H2 leak
Other
100%
4%
?%
-5 to 105%, no alarm
0-4%, alarm 1%
Customer specified
Standard
On request
On request
Other options
Inquire
Customer-specific alterations
On request
Accessories for the XEN-5310 sensor, available separately
XEN-85000
PCB with FTDI interface chip to connect up to 4 XEN-5310 to a PC via USB.
Cable pack 2 Custom specified cable for XEN-5310.
Cable pack 4 Cable of 50 cm, with AMP connectors 2x4 rows on both sides, for connection of
the sensor to the FTDI PCB.
Disclaimer: No responsibility is taken for the consequences of improper functioning of the sensor.
Conditions: Use of sensors for industrial applications is subjected to patent rights. Xensor Integration assumes no liability
arising from violation of these rights
Warranty: Xensor Integration warrants its products against defects in materials and workmanship for 12 months from date
of shipment. Products not subject to misuse will be replaced or repaired. The foregoing is in lieu of all other
expressed or implied warranties. Xensor Integration reserves the right to make changes to any product herein
and assumes no liability arising out of the application or use of any product or circuit described or referenced
herein.
Xensor Integration bv
Distributieweg 28
2645 EJ Delfgauw
The Netherlands
copyright Xensor Integration
Smart Sensor Devices
Phone +31 (0)15-2578040 Founded 18 May 1988 ABN-AMRO 60 50 40 311
Fax
+31 (0)15-2578050 Trade reg. 27227437 IBAN NL42ABNA060504031
1
Email
[email protected] Site
www.xensor.nl
VAT NL 009122746 B01
12 October 2015
page 7 of 7