Related Manuals for Hukseflux STP01
Summary of Contents for Hukseflux STP01
- Page 1 USER MANUAL STP01 Soil temperature profile sensor with self-test Copyright by Hukseflux | manual v1627 | www.huksefluxusa.com | info@huksefluxusa.com...
-
Page 2: Warning Statements
Putting more than 15 Volt across the heater wiring can lead to permanent damage to the heater. Do not use “open circuit detection” when measuring the thermocouple sensor output. STP01 manual v1627 2/31... -
Page 3: Table Of Contents
Ordering and checking at delivery Ordering STP01 Included items Quick instrument check Instrument principle and theory General soil temperature measurement STP01 soil temperature measurement STP01 on-line self-test Optional thermal conductivity measurement Conformity testing and traceability Programming Specifications of STP01 Dimensions of STP01... -
Page 4: List Of Symbols
Depth of installation Distance from the heater Subscripts property of a sensor sensor property of the reference temperature Pt100 reference property at the (soil) surface surface property of the surrounding soil soil property of the heater heater STP01 manual v1627 4/31... -
Page 5: Introduction
When activating the heater for a self-test, this will lead to a local increase in temperature at the sensors at 0.02, 0.05, 0.1 and 0.2 m depth. The STP01 stability is monitored by analysis of yearly patterns of this step-response. - Page 6 Equipped with heavy duty cabling, and potted so that moisture does not penetrate the sensor, STP01 has proven to be very robust and stable. It survives long-term installation in soils. For ease of installation with a minimum of disturbance of the local soil, Hukseflux offers IT01 insertion tool.
- Page 7 Figure 0.2 STP01 layout and dimensions 1 soil surface 2 sensor foil (0.6 x 10 m thickness, 2.5 x 10 m at Pt 100) 3 2 x cable 5 m (see options) 4 copper leads 5 T type thermocouple wire...
- Page 8 (2 x), in multiples of 5 m, cable lengths above 20 m in multiples of 10 m insertion tool IT01 Figure 0.3 IT01 insertion tool is hammered down into the soil. After retracting it leaves a slit in which STP01 may be inserted. See also: model...
-
Page 9: Ordering And Checking At Delivery
Ordering and checking at delivery 1.1 Ordering STP01 The standard configuration of STP01 is with 2 x 5 metres cable. Common options are: longer cable in multiples of 5 m, cable lengths above 20 m in multiples of 10 m. -
Page 10: Instrument Principle And Theory
STP01 overcomes the traditional shortcomings: STP01 uses a string of thermocouples type T sharing one and the same CuNi wire and the same Cu wire (made from the same sheet). We claim that the thermocouples are “matched”, i.e. have the same properties. The relative accuracy of such matched thermocouples is better than 0.05 °C. -
Page 11: Stp01 On-Line Self-Test
Typically every 24 hours, the STP01 heater is switched on for 600 s to perform a self- test. When activating the heater for a self-test, this will lead to a local increase in temperature at the sensors at 0.02, 0.05, 0.1 and 0.2 m depth. -
Page 12: Conformity Testing And Traceability
(Formula 2.4.2) 2.5 Conformity testing and traceability During manufacturing STP01 has to pass an acceptance test. In the test we verify if the properties of the thermocouples, Pt100 and heating wire are within specifications. If the specified sensors are manufactured as required, we consider them traceable to SI. We rely on their material specifications which we verify by electrical resistance measurement. -
Page 13: Programming
In case the user writes his own software program for controlling the measurement with STP01, the program flow in table 2.6.1 may be used. Table 2.6.1 a summary of a program for control of the measurement with STP01 initialisation enter sensor and system... -
Page 14: Specifications Of Stp01
Specifications of STP01 STP01 measures the temperature profile of the soil at 5 depths close to its surface. It is designed for long-term monitoring of soils. Good thermal contact between soil and sensor is required. The on-line self-test, using the incorporated heating wire, offers a solution for on-site verification of STP01’s functionality and measurement stability. - Page 15 Table 3.1 Specifications of STP01 (started on previous page, continued on next page) Sensor foil surface dimensions (500 x 35) x 10 Sensor foil thickness 0.6 x 10 2.5 x 10 m at Pt100 Connector block dimensions (40 x 42 x 10) x 10 Thermocouple sensor resistance range 5 Ω...
- Page 16 Table 3.1 Specifications of STP01 (started on previous pages) CONFORMITY TESTING AND TRACEABILITY Factory conformity testing the STP01 functional test compares the electrical resistance of the produced sensor against the acceptance interval. This is done for the thermocouples, Pt100 and heater.
-
Page 17: Dimensions Of Stp01
Dimensions of STP01 Figure 3.1.1 STP01 soil temperature profile dimensions in x 10 (1) soil surface (2) sensor foil (0.6 x 10 m thickness, 2.5 x 10 at Pt 100) (3) 2 x cable (standard length 5 m, optionally longer... -
Page 18: Standards And Recommended Practices For Use
Standards and recommended practices for use STP01 sensors measure temperature as a function of depth in soils, as part of meteorological surface flux measuring systems. Typically the total measuring system consists of multiple heat flux- and temperature sensors, often combined with measurements of air temperature, humidity, solar- or net radiation and wind speed. -
Page 19: Installation Of Stp01
Installation of STP01 5.1 Site selection and installation Table 5.1.1 Recommendations for installation of STP01 Location Preferably install in a large field which is relatively homogeneous and representative of the area under observation. Depth The top of the sensor should be 0.01 m below the soil surface... -
Page 20: Electrical Connection
5.2 Electrical connection An STP01 must be connected to a measurement and control system, typically a so-called datalogger. STP01’s thermocouple sensors are passive sensors that do not need any power. The Pt100 needs a low-power voltage excitation. The heater is powered from 9 to 15 VDC, using a user-supplied relay to switch it on and off. - Page 21 Grey not connected not connected Black ground shield / ground Table 5.2.2 connections of the STP01 cable 2. The wires extend 0.15 m from the cable end. CABLE # WIRE FUNCTION MEASURING SYSTEM Yellow heater measure [+] analogue voltage [+]...
-
Page 22: Stp01 Diagnostics
5.3 STP01 diagnostics The following tables are use for checking and trouble shooting STP01. Table 5.3.1 Resistance checks for diagnostics of STP01 cable 1 RESISTANCE ACCEPTANCE CABLE # WIRE WIRE INTERVAL Brown Green 2.5 Ω plus 0.4 Ω/m cable (approx.) Brown 3.5 Ω... -
Page 23: Requirements For Data Acquisition / Amplification
5.4 Requirements for data acquisition / amplification The selection and programming of dataloggers is the responsibility of the user. To see if directions for use with STP01 are available: contact the supplier of the data acquisition equipment. Table 5.4.1 Requirements for data acquisition, amplification and control equipment for... -
Page 24: Making A Dependable Measurement
6.2.2 measurement uncertainties for the reference temperature measurement STP01 is equipped with a Pt100 platinum resistance thermometer. It is classified as class B according to DIN EN 60751. It has a resistance of 100 Ω at a temperature of 0 °C. - Page 25 6.2.3 Differential measurement with matched thermocouples Hukseflux estimates that matched thermocouples type T measure temperature differences with an uncertainty of better than 1.5 % in the -20 to + 70 °C temperature range. This estimate is based on their linearity specification in that temperature range.
-
Page 26: Maintenance And Trouble Shooting
Maintenance and trouble shooting 7.1 Recommended maintenance and quality assurance STP01 measures reliably at a low level of maintenance. Unreliable measurement results are detected by scientific judgement, for example by looking for unreasonably large or small measured values during the self-test. The preferred way to obtain a reliable measurement is a regular critical review of the measured data, preferably checking against other measurements. -
Page 27: Trouble Shooting
7.2 Trouble shooting Table 7.2.1 Trouble shooting for STP01 General Inspect the quality of installation. Inspect if the wires are properly attached to the data logger. Check the condition of the cables. Inspect the connection of the shields (typically connected at the datalogger side). - Page 28 STP01 manual v1627 28/31...
-
Page 29: Appendices
Thermal offsets cause errors when they interfere with small thermocouple voltages. STP01 is equipped with two cables. Keep the distance between data logger or amplifier and sensor as short as possible. Cables may act as a source of distortion by picking up capacitive noise. -
Page 30: Eu Declaration Of Conformity
8.2 EU declaration of conformity Hukseflux Thermal Sensors B.V. Delftechpark 31 2628 XJ Delft The Netherlands in accordance with the requirements of the following directive: 2014/30/EU The Electromagnetic Compatibility Directive hereby declare under our sole responsibility that: Product model: STP01... - Page 31 © 2016, Hukseflux Thermal Sensors B.V. www.hukseflux.com Hukseflux Thermal Sensors B.V. reserves the right to change specifications without notice.
Need help?
Do you have a question about the STP01 and is the answer not in the manual?
Questions and answers