Specifications and components
The central TSA2 is a stand-alone, general-purpose thermocouple scanner / amplifier / AD converter, which can be expanded in various ways. The most well known use is in the IAVS-M2 systems (see below for details), which provides the interface between the measuring sensors and the software in a (portable) computer, which registers and records the measurements in charts and tables.
TSA2 Thermocouple scanner basic version with laptop:
The TSA2 thermocouple scanner / amplifier / AD converter is the heart of the measurement system and contains all the necessary electronics for reading the analog signals from the various sensors and convert it to digital information . The embedded micorprocessor in TSA2 communicates digital measurement data with the externally connected personal computer and also processes control commands of the PC for setup and operation of the measurement system . The electronics with the stored calibration data included is dimensioned such that the standardized measurement accuracy can be guaranteed.
- Each analog thermocouple signal is converted to digital signal at a precision of 16 bits; in this range this means a real accuracy of at least 0.01 °C for the conversion, including the physical thermocouple thus an accuracy of 0.25 °C can be acheived.
- The scanner comes including:
- USB cable to connect the TSA2 with the personal computer;
- 4 m frame grounding wire;
- separate 230 V power supply.
- Implementation with either separate thermocouple connectors or combined Sub-D connectors for easy connection / change of thermocouple sets;
- Extensions from 8 to 16, 24 up to 32 additional thermocouple inputs
Pressure sensor inputs
- including connection for temperature conditioning for maximum accuracy of pressure measurements (see temperature controlled pressure sensor below)
General purpose AD-inputs (16 bits; female, 5-pens, DIN 270, 4 - 20 mA):
- universal 4-20 mA input to connect others types of standard sensor
- conection for the automated control of the MBO thermocouple calibration system (metal block oven with ITCS)
- for a swithed detection of transitions in process phases. A unique feature is the ability to connect this input by means of a relay to the sterilizer control system, with which the exact phase transition of that control can be detected.
Thermocouple wire per meter:
- type K, twin twist (BS 4937, Part 30. 1993; IEC 584-3; green/white)
- type K, twin flat (BS 1843:1952; green)
The use of type K or type J thermocouples is recommended. For these types linearisation hardware is standard available (IC), resulting in a situation with high accuracy. But for type T thermocouples additional hardware could be integrated (recalibration with resistors). The lesser accuracy can than be improved by software.
Thermocouples are available as separate elements, on one side provided with a thermocouple connector and on the other side finished with a soldered point and insulation. Type and the length are at your choise.
Several individual thermocouples are assembled to thermocouple sets with or without a pressure tight feedthrough. The various elements of the set are then provided a number marking to recognize Individual thermocouples.
Thermocouple sets are fitted:
- with separate loose connectors (male)
- or with a Sub-D connector (male)
- shielded according to EMC directives (only when using Sub-D connectors) and
- with or without individual pressure tight feedthroughs entries (up to 400 kPa abs) combined in a stainless steel cap.
Standard thermocouple sets have 8, 10 or 16 thermocouples (10 m, twin twist / flat).
Other configurations of thermocouple sets are available on request, for example:
- shorter or longer couples (in sets with feedthroughs) or
- other numbers of thermocouples.
- separate thermocouple connector (type K)
- 1 Sub-D thermocouple connector (type K; 37-pens for 16 thermocouples) for the easy connection / change of sets
Twin flat in stead of twin twist wire (surcharge):
- per 8 m
- per set of 8 thermocouples (8 m)
- per set of 16 thermocouples (8 m)
Stainless steel, pressure tight feedthroughs:
- feedthrough with 8, 12 or 16 thermocouples
- pressure up to at least 400 kPa absolute
- to provide with an Y-coupler for connecting multiple thermocouple sets simultaneously
- to provide with a T-connection piece for the connection of pressure sensors
- feedthroughs are supplied with a coupler/gradient with 0.5" inner screw thread, other couplers/gradients are available on request.
We make a distinction with regard to pressure sensors in accuracy and stability. For example, two pressure sensors can have the same accuracy, but the stability, among other things as a result of temperature variations of one of the two pressure sensors, may be such that the accuracy can not be guaranteed over a longer period of time. Our pressure sensors are supplied in adequate housing, equipped with all necessary cabling, power supplies, etc. Moreover there is also the possibility of connecting your own separate pressure sensor.
Pressure sensor in a temperature conditioned version
This pressure sensor is ideally suited for measuring the vessel pressure during steam sterilization processes:
- galvanic separation by means of opto-couplers
- Stainless steel cooling of the medium / steam "outside" the sensor element
- controlled compensation of ambient temperature and
- built-in temperature compensation of the AD converter electronics.
This pressure sensing system has a range of 0 to 400 kPa and an accuracy of 0.17%, so 0.7 kPa. A change in temperature of 0.1 °C at 134 °C means a change in pressure of 0.8 kPa. Measuring a minimal change in theoretical temperature of 0.1 ºC in response to a pressure change, such as required by the standards and as done during validation of steam sterilizers, can thus be realized with this accuracy of the pressure sensor, as well as a reliable signaling of eg. superheated steam.
Due to the temperature compensation the accuracy stability can be guaranteed for at least a year, so a 1 x annual calibration can suffice.
Because the system can read the temperature of the pressure sensor, it is possible to monitor the integrity of the pressure readings in a given measurement period.
- A pressure sensor is supplied with a calibration certificate traceable to international standards.
- A pressure sensor can be mechanically provided with a "knee"-type coupler to connect a thermocouple set ("combined feedthrough").
Calibration system (MBO)
The TSA2 can be extended with the option for a metal block oven (MBO):
- for the calibration of the thermocouples connected to TSA2;
- for temperature stabilization of all sorts of sensors (eg. to calibrate pt100s of sterilizers).
The option includes:
- an extension of TSA2 (hardware and software);
- the metal block oven itself;
- the cable between TSA2 and oven;
- a calibration certifcate traceable to international standards.
In combination with the TSA2, the metal block oven has the following properties:
- four or five 8-mm holes, drilled around a heating element, approximately 190 mm deep, one of which can be used for the independent temperature control systems (see below); the control signal is electrically isolated from the 230 V AC power supply;
- the metal block oven is controlled by a pt100, placed in the middle of the holes at the insertion depth of the thermocouples during calibration;
With respect to the reference amplifier for the pt100 holds:
- 16-bit digital accuracy; drift 20 ppm per year, overall accuracy 0.05 °C;
- self-correcting, temperature compensated control and measurement electronics;
- galvanic isolated from the computer by means of opto-couplers (16 bit AD converter is internally shielded).
For the metal block oven option, in combination with the thermocouple calibration facility, an accuracy of 0.1 °C is guaranteed.
- stability 0.05 ºC for at least 1 year;
- range 35 - 220 ºC;
- set point accuracy 0.1 ºC;
- reading accuracy 0.01 ºC and
- ambient temperature 10 - 30 º C.
For a improved placement and thermal stabilization of the thermocouples during the calibration procedure, it is advisable to make use of so-called thermocouple heating tubes:
- Sets of thermocouple heating tubes with 6 holes for 6 thermocouples.
Programmable calibration procedures
A particular advantage of this metal block oven is its ability to execute programmable calibration procedures in combination with the ValidR validation software. After a one-time setup of the desired calibration points (up to 10 points are allowed), they are automatically run through under the control of the TSA2 and ValidR. It is also possible to enter a desired point of time at which the calibration procedure is then started automatically. By means of this integrated functionality, the entire calibration procedure can be carried out independently and unattended.
Independant temperature control system (ITCS)
In order to independently monitor the temperature of the metal block oven (MBO) during calibration use can be made of a Catch-T model ITCS with pt100 sensor and separate digital readout:
- range -30 to +225 °C;
- system accuracy 0.05 °C (sensor + wiring + electronics) and
- resolution 0.01 ºC
- for further details see also the Catch-T Temperature Measurement webpage.
The Catch-T ITCS is also supplied with a calibration certificate traceable to international standards.