Metrological Aspects of Auto-normalized Front Photopyroelectric Method to Measure Thermal Effusivity in Liquids

Gutiérrez-Juárez, G.; Ivanov, R.; Pichardo-Molina, J. P.; Vargas-Luna, M.; Alvarado‐Gil, J. J.; Camacho, A P Alma

doi:10.1007/s10765-007-0261-4

Cited by 5 publications

(5 citation statements)

References 8 publications

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“…As mentioned in section 1, the EPE technique can be applied in two configurations, the so-called i-EPE and d-EPE techniques. To obtain the frequency dependence of the EPE signal, in the former case one can use the well-known inverse PPE technique theory described elsewhere [10] by substituting the maximal laser power, P 0 , by the maximal electrical power of the component of equation ( 2) with frequency ω, namely P e = 2I 2 m R. Thus we have for the PE voltage…”

Section: Description Of the Methodsmentioning

confidence: 99%

Electropyroelectric technique for measurement of the thermal effusivity of liquids

Ivanov¹,

Marı́n²,

Moreno³

et al. 2010

J. Phys. D: Appl. Phys.

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The photopyroelectric method has been recognized as a reliable and useful tool for the measurement of the thermal properties of condensed matter samples. Usually the photothermal signal is generated using intensity modulated light beams, whose amplitudes are difficult to maintain stable. In this paper we describe a variant of this technique that uses amplitude modulated electrical current as excitation source, via Joule heating of the metal contact on one side of the pyroelectric sensor. The possibilities of this method, called by us the electropyroelectric technique, for thermal effusivity measurements of liquid samples are shown using test samples of distilled water, ethanol and glycerine. The results obtained for this parameter agree well with the values reported in the literature. Our measurement uncertainties are about 3%, a fact that opens several possible applications.

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Section: Description Of the Methodsmentioning

confidence: 99%

Electropyroelectric technique for measurement of the thermal effusivity of liquids

Ivanov¹,

Marı́n²,

Moreno³

et al. 2010

J. Phys. D: Appl. Phys.

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“…As seen in figure 14, the amplitude values are proportional to e. In the range from 0.01 to 20 Hz, the amplitude increases as a function of the frequency and then rapidly decreases. The different behaviours of the amplitude for the ideal voltage mode and for the ideal current mode occur because the B 0 coefficient (equation (16)) is directly proportional to the frequency ω. By comparing figures 10 and 14, it can be seen that the voltage mode is better than the current mode because the signal-tonoise ratio is greater in the first mode for the same measurement conditions.…”

Section: Numerical Evaluations and Discussionmentioning

confidence: 99%

“…The accuracy of single (non-differential) FPPE cell is limited by the external noises and uncertainties of the experimental setup [16,17].…”

Section: Choice Of the Electrical Circuitmentioning

confidence: 99%

Differential sensor in front photopyroelectric technique: I. Theory

Ivanov

Gutiérrez-Juárez

Pichardo‐Molina

et al. 2008

J. Phys. D: Appl. Phys.

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In this paper the theory of the differential front photopyroelectric technique is developed. The thermal effusivity measurements of a sample through photopyroelectric direct (no-differential) experiments do not have sufficient resolution and accuracy to detect small changes in the thermal effusivity. To assess minor variations in this thermal magnitude, differential methods should be used. These methods compare properties of a reference sample and another unknown sample, which are placed separately in both halves of the differential cell. It is shown that in order to achieve better metrological properties of the differential measurement and electromagnetic interference immunity, the signals of both halves must be subtracted directly at the output of the two parallel connected pyroelectric sensors. The thickness of the samples should have the maximum possible value, at least 10 times higher than the thermal diffusion length for minimum frequency. The results of numerical simulations for the amplitude, phase, real and imaginary parts with water as a reference sample and the other sample with a thermal effusivity very close to that of water (contaminated water) are presented. These results show that measurements should be made in the nearly ideal voltage mode, which ensures a better signal-to-noise ratio than the ideal current mode.

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“…Their thermal diffusivity and effusivity measurements were obtained with high accuracy (within 0.5%), and the results were sensitive to changes in the relevant parameters of the nanofluid as the base fluid, concentration and type of NPs. Thus, the front PPE method [13][14][15][35][36][37][38][39] was a suitable for accurate and simultaneous measurements of thermal diffusivity and effusivity of nanofluids.…”

Section: Thermal Effusivity Measurement Techniquesmentioning

confidence: 99%

“…In this technique, the light modulation impinges on the front surface of a sample and the PE sensor, located in good thermal contact with the sample's backside so the PE signal can be measured by performing either a frequency or a cavity length scan. The back and front PPE configurations in 'thermally thick' conditions have been reported to measure the thermal diffusivity and thermal effusivity of a sample [39,44]. A front PPE technique is the modification of the classical configuration of the PPE technique.…”

Section: Theoretical Background: Photopyroelectric Techniquementioning

confidence: 99%

Measuring Nanofluid Thermal Diffusivity and Thermal Effusivity: The Reliability of the Photopyroelectric Technique

Noroozi¹,

Zakaria²

2017

Nanofluid Heat and Mass Transfer in Engineering Problems

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It is important to study nanofluids to understand their extraordinary thermal properties and how the size, concentration and agglomeration of the nanoparticles affect those properties. Photopyroelectric (PPE) technique has been well established in the use of non-destructive measurement of thermal diffusivity and thermal effusivity, by using polyvinylidene fluoride (PVDF) films as sensitive pyroelectric sensors in thermally thick conditions instead of using very thick ceramic sensors. There have been two proposed practical configurations for the PPE technique, the back and the front PPE configurations, to obtain both the thermal diffusivity and effusivity, which are suitable thermal parameters of materials. This PPE technique involves the measurement of thermal waves in the sample due to absorption of optical radiation, by placing a pyroelectric sensor in thermal contact with the sample. This chapter provides a review of the back and the front PPE configurations to determine the thermal diffusivity and effusivity of nanofluids, sample preparation techniques using high-amplitude ultrasonic dispersion and data analysis for metal oxide-based nanofluid materials.

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Metrological Aspects of Auto-normalized Front Photopyroelectric Method to Measure Thermal Effusivity in Liquids

Cited by 5 publications

References 8 publications

Electropyroelectric technique for measurement of the thermal effusivity of liquids

Electropyroelectric technique for measurement of the thermal effusivity of liquids

Differential sensor in front photopyroelectric technique: I. Theory

Measuring Nanofluid Thermal Diffusivity and Thermal Effusivity: The Reliability of the Photopyroelectric Technique

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