Experiments on thermal drift

2021 ◽  
Vol 33 (8) ◽  
pp. 087116
Author(s):  
A. Inasawa ◽  
K. Hara ◽  
J. M. Floryan
Keyword(s):  
Author(s):  
Louis T. Germinario

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).


Author(s):  
P.R. Swann ◽  
A.E. Lloyd

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.


Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1357
Author(s):  
Linxiao Cong ◽  
Jianchao Mu ◽  
Qian Liu ◽  
Hao Wang ◽  
Linlin Wang ◽  
...  

The space gravitational wave detection and drag free control requires the micro-thruster to have ultra-low thrust noise within 0.1 mHz–0.1 Hz, which brings a great challenge to calibration on the ground because it is impossible to shield any spurious couplings due to the asymmetry of torsion balance. Most thrusters dissipate heat during the test, making the rotation axis tilt and components undergo thermal drift, which is hysteretic and asymmetric for micro-Newton thrust measurement. With reference to LISA’s research and coming up with ideas inspired from proportional-integral-derivative (PID) control and multi-timescale (MTS), this paper proposes to expand the state space of temperature to be applied on the thrust prediction based on fine tree regression (FTR) and to subtract the thermal noise filtered by transfer function fitted with z-domain vector fitting (ZDVF). The results show that thrust variation of diurnal asymmetry in temperature is decoupled from 24 μN/Hz1/2 to 4.9 μN/Hz1/2 at 0.11 mHz. Additionally, 1 μN square wave modulation of electrostatic force is extracted from the ambiguous thermal drift background of positive temperature coefficient (PTC) heater. The PID-FTR validation is performed with experimental data in thermal noise decoupling, which can guide the design of thermal control and be extended to other physical quantities for noise decoupling.


2017 ◽  
Vol 17 (6) ◽  
pp. 881-885 ◽  
Author(s):  
Luigi Guerriero ◽  
Giovanni Guerriero ◽  
Gerardo Grelle ◽  
Francesco M. Guadagno ◽  
Paola Revellino

Abstract. Continuous monitoring of earth flow displacement is essential for the understanding of the dynamic of the process, its ongoing evolution and designing mitigation measures. Despite its importance, it is not always applied due to its expense and the need for integration with additional sensors to monitor factors controlling movement. To overcome these problems, we developed and tested a low-cost Arduino-based wire-rail extensometer integrating a data logger, a power system and multiple digital and analog inputs. The system is equipped with a high-precision position transducer that in the test configuration offers a measuring range of 1023 mm and an associated accuracy of ±1 mm, and integrates an operating temperature sensor that should allow potential thermal drift that typically affects this kind of systems to be identified and corrected. A field test, conducted at the Pietrafitta earth flow where additional monitoring systems had been installed, indicates a high reliability of the measurement and a high monitoring stability without visible thermal drift.


1997 ◽  
Vol 33 (9) ◽  
pp. 780 ◽  
Author(s):  
A.A. Saavedra ◽  
R. Passy ◽  
J.P. von der Weid

1965 ◽  
Vol 53 (5) ◽  
pp. 556-556
Author(s):  
B. Murari
Keyword(s):  

2014 ◽  
Vol 11 (3) ◽  
pp. 501-521
Author(s):  
Sasa Skoko ◽  
Darko Marcetic ◽  
Veran Vasic ◽  
Djura Oros

The detailed presentation of modern algorithm for the rotor speed estimation of an induction motor (IM) is shown. The algorithm includes parallel speed and resistance parameter estimation and allows a robust shaft-sensorless operation in diverse conditions, including full load and low speed operation with a large thermal drift. The direct connection between the injected electric signal in the d-axis and the component of injected rotor flux were pointed at. The algorithm that has been applied in the paper uses the extracted component of the injected rotor flux in the d-axis from the observer state vector and filtrated measured electricity of one motor phase. By applying the mentioned algorithm, the system converges towards the given reference.


2021 ◽  
Vol 6 (1) ◽  
pp. 34
Author(s):  
Serigne Modou Die Mbacke ◽  
Mohammed El Gibari ◽  
Benjamin Lauzier ◽  
Chantal Gautier ◽  
Hongwu Li

Implantable pressure sensors represent an important part of the research activity in laboratories. Unfortunately, their use is limited by cost, autonomy and temperature-related drifts. The cost of use depends on several parameters, particularly their low battery life and the need for miniaturization to be able to implant the animals and monitor them over a time that is long enough to be physiologically relevant. This paper studied the possibility of reducing the thermal drift of implantable sensors. To quantify and compensate for the thermal drift, we developed the equivalent model of the piezoresistive probe by using the Cadence software. Our model takes into account the temperature (34–39 °C) as well as the pressure (0–300 mmHg). We were thus able to identify the source of the drift and thanks to our model, we were able to compensate for it thanks to the compensation circuits added to the conditioning circuits of the sensor. The maximum relative drift of the sensor is (0.1 mV/°C)/3.6 mV (2.7%), a drift of the conditioning circuit is (0.98 mV/°C)/916 mV (0.1%) and the whole is (13.4 mV/°C)/420 mV (32%). The compensated sensor shows a relative maximum drift of (0.371 mV/°C)/405 mV (0.09%). The output voltage remains stable over the measurement temperature range.


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