Evaluation of Measurement Errors of Tipping Bucket Rain Gauges

The observation accuracy of rainfall processes affects every aspects of the meteorological and hydrological affairs, which is widely monitored by various types of tipping bucket rain gauges&#65288;TBRs&#65289;because of the simple structure and reliable performance. The study of the measurement errors of TBRs is quite valuable and necessary for improving the rainfall data quality and evaluating the uncertainty of the research based on the dataset.In this study, an artificial rainfall and monitor experiment system is designed with peristaltic pump, balances, recorder and controller for the accurate rainfall and the TBRs instrumental values record, based on which the error distribution and instrument stability were analyzed. Eight types of TBRs are chose for the error evaluation experiment, including five single-layer TBRs, three double-layer TBRs. For each TBRs, we observe its performance under 6 rain intensity (0.1-4mm/min) in turn. With regard to each rain intensity, when the simulated total rainfall reaches 10 mm, the experiment stops and records the data, then repeats the same experiment 6 times.The result shows that the single-layer TBRs have a good linear relationship between the rainfall and the measurement error, and the double-layer TBRs has a significant regulating effect on the continuous heavy rain intensity, which can make the rain flow steadily down to the lower tipping bucket (metering tipping bucket) with a stable rain intensity to avoid the rain intensity variation influence on the measurement error. However, due to its high resolution of 0.1mm, it is greatly affected by the residual water volume of the tipper bucket.According to the results, the single-layer TBRs can correct the actual rainfall measurement process according to the error ~ rainfall intensity curve. The double-layer TBRs can play an important role in the rainy day record, but the randomness of the residual in the tipping bucket needs to be further estimated. Because the proportion of the light rainfall intensity in most of the rainfall events are quite high according to the statistics, it is necessary to have lower measurement error under the light rainfall in the TBRs chosen and calibration process. It's a good idea to choose a combination of rain gauges(0.1mm&0.5mm) to improve the accuracy of rainfall and rainy day.

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Investigation of Tipping-Bucket Rain Gauges Using Digital Photographic Technology

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-19-0064.1 ◽

2020 ◽

Vol 37 (2) ◽

pp. 327-339 ◽

Cited By ~ 2

Author(s):

Minhan Liao ◽

Jiufu Liu ◽

Aimin Liao ◽

Zhao Cai ◽

Yixin Huang ◽

...

Keyword(s):

Traditional Method ◽

Rainfall Intensity ◽

Rain Gauge ◽

Recording Device ◽

Calculation Formula ◽

Rain Intensity ◽

Primary Interest ◽

Rain Gauges ◽

Variation Characteristics ◽

New Formula

AbstractWhen studying the tipping-bucket rain gauge (TBR), it is rather difficult to make an objective and sophisticated measurement of the duration of bucket rotation. From the perspective of digital photographic technology, however, the problem can be easily solved. The primary interest of this research has been to use digital photographic technology to study the TBR under laboratory conditions. In this study, the interframe difference algorithm and a camera recording device were used. Based on three types of JDZ TBRs, the time variation characteristics of bucket rotation were obtained. The time from the beginning of a tip to the time that the bucket is horizontal T1 and the time for a complete tip T2 were analyzed in detail. The results showed that T1 and T2 were functions of rainfall intensity, and T1 and T2 decrease as the rain intensity increases significantly (P < 0.001). Moreover, excellent evidence shows that the averages of T1 and T2 were positively correlated with bucket mass. It took more time for the bucket to tip as the mass of the bucket increased. Furthermore, the error of each TBR was calculated by the new proposed error calculation formula, and the new method was compared with the traditional method. The results from the two methods were very close, which demonstrates the correctness and feasibility of the new formula. However, the traditional calibration cannot acquire the variation characteristics of the tipping time, but the proposed approach can achieve this.

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Performance of post-processing algorithms for rainfall intensity using measurements from tipping-bucket rain gauges

Atmospheric Measurement Techniques ◽

10.5194/amt-9-5699-2016 ◽

2016 ◽

Vol 9 (12) ◽

pp. 5699-5706 ◽

Cited By ~ 6

Author(s):

Mattia Stagnaro ◽

Matteo Colli ◽

Luca Giovanni Lanza ◽

Pak Wai Chan

Keyword(s):

Time Resolution ◽

Rainfall Intensity ◽

Single Layer ◽

Time Algorithm ◽

Post Processing ◽

Sampling Errors ◽

Rain Gauges ◽

Virtual Time ◽

Processing Algorithms ◽

Rain Events

Abstract. Eight rainfall events recorded from May to September 2013 at Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the rainfall intensity (RI) from tipping-bucket rain gauges (TBRGs). We assumed a drop-counter catching-type gauge as a working reference and compared rainfall intensity measurements with two calibrated TBRGs operated at a time resolution of 1 min. The two TBRGs differ in their internal mechanics, one being a traditional single-layer dual-bucket assembly, while the other has two layers of buckets. The drop-counter gauge operates at a time resolution of 10 s, while the time of tipping is recorded for the two TBRGs. The post-processing algorithms employed for the two TBRGs are based on the assumption that the tip volume is uniformly distributed over the inter-tip period. A series of data of an ideal TBRG is reconstructed using the virtual time of tipping derived from the drop-counter data. From the comparison between the ideal gauge and the measurements from the two real TBRGs, the performances of different post-processing and correction algorithms are statistically evaluated over the set of recorded rain events. The improvement obtained by adopting the inter-tip time algorithm in the calculation of the RI is confirmed. However, by comparing the performance of the real and ideal TBRGs, the beneficial effect of the inter-tip algorithm is shown to be relevant for the mid–low range (6–50 mmh−1) of rainfall intensity values (where the sampling errors prevail), while its role vanishes with increasing RI in the range where the mechanical errors prevail.

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Performance of post-processing algorithms for rainfall intensity measurements of tipping-bucket rain gauges

10.5194/amt-2016-257 ◽

2016 ◽

Author(s):

Mattia Stagnaro ◽

Matteo Colli ◽

Luca Giovanni Lanza ◽

Pak Wai Chan

Keyword(s):

Time Resolution ◽

Rainfall Intensity ◽

Single Layer ◽

Time Algorithm ◽

Post Processing ◽

Sampling Errors ◽

Rain Gauges ◽

Intensity Measurements ◽

Processing Algorithms ◽

Rain Events

Abstract. A number of rain events recorded from May to September 2013 at the Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the Rainfall Intensity (RI) from Tipping-Bucket Rain Gauges (TBRGs). We assumed a drop counter catching-type gauge as a working reference and compared rainfall intensity measurements with two calibrated TBRGs operated at a time resolution of 1 min. The two TBRGs differ in their internal mechanics, one being a traditional single-layer dual-bucket assembly, while the other has two layers of buckets. The drop counter gauge operates at a time resolution of 10 s, while the time of tipping is recorded for the two TBRGs. The post-processing algorithms employed for the two TBRGs are based on the assumption that the tip volume is uniformly distributed over the inter-tip period. A series of data of an ideal TBRG is reconstructed using the virtual time of tipping derived from the drop counter data. From the comparison between the ideal gauge and the measurements from the two real TBRGs the performance of different post-processing and correction algorithms are statistically evaluated over the set of recorded rain events. The improvement obtained by adopting the inter-tip time algorithm in the calculation of the RI is confirmed. However, by comparing the performance of the real and ideal TBRGs, the beneficial effect of the inter-tip algorithm is shown to be relevant for the mid-low range of rainfall intensity values (where the sampling errors prevail), while its role vanishes with increasing the RI, in the range where the mechanical errors prevail.

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Investigation of tipping bucket rain gauges using digital photographic technology

10.5194/egusphere-egu2020-1931 ◽

2020 ◽

Author(s):

Minhan Liao ◽

Jiufu Liu ◽

Aimin Liao

Keyword(s):

Traditional Method ◽

Rainfall Intensity ◽

Rain Gauge ◽

Recording Device ◽

Calculation Formula ◽

Rain Intensity ◽

Primary Interest ◽

Rain Gauges ◽

Variation Characteristics ◽

New Formula

When studying the tipping bucket rain gauge (TBR), it is rather difficult to make an objective and sophisticated measurement of the duration of bucket rotation. From the perspective of digital photographic technology, however, the problem can be easily solved. The primary interest of this research has been to use digital photographic technology to study the TBR under laboratory conditions. In this study, the interframe difference algorithm and a camera recording device were used. Based on three types of JDZ TBRs, the time variation characteristics of bucket rotation were obtained. The time from the beginning of a tip to the time that the bucket is horizontal (T1) and the time for a complete tip (T2) were analyzed in detail. The results showed that T1 and T2 were functions of rainfall intensity, and T1, T2 decrease as the rain intensity increases significantly (P<0.001). Moreover, excellent evidence shows that the averages of T1 and T2 were positively correlated with bucket mass. It took more time for the bucket to tip as the mass of the bucket increased. Furthermore, the error of each TBR was calculated by the new proposed error calculation formula, and the new method was compared with the traditional method. The results from the two methods were very close, which demonstrates the correctness and feasibility of the new formula. However, the traditional calibration cannot acquire the variation characteristics of the tipping time, but the proposed approach can achieve this.

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Analysis of highly accurate rain intensity measurements from a field test site

Advances in Geosciences ◽

10.5194/adgeo-25-37-2010 ◽

2010 ◽

Vol 25 ◽

pp. 37-44 ◽

Cited By ~ 16

Author(s):

L. G. Lanza ◽

E. Vuerich ◽

I. Gnecco

Keyword(s):

Rainfall Intensity ◽

Test Site ◽

Quality Data ◽

Rain Intensity ◽

Data Set ◽

High Quality Data ◽

Operational Conditions ◽

Rain Gauges ◽

Intensity Measurements ◽

Instrument Intercomparison

Abstract. In the course of the recent WMO international instrument intercomparison in the field and the associated specific laboratory tests, highly accurate rainfall intensity measurements have been collected and made available for scientific investigation. The resulting high quality data set (contemporary one-minute rainfall intensity data from 26 gauges based on various measuring principles) constitutes an important resource to provide insights into the expected behaviour of rain intensity gauges in operational conditions and further useful information for National Meteorological Services and other users. A few aspects of the analysis of one-minute resolution rain intensity measurements are discussed in this paper, focusing on the observed deviations from a calculated reference intensity based on four pit gauges. Results from both catching and non-catching type gauges are discussed in relation with suitable tolerance limits obtained as a combination of the estimated uncertainty of the reference intensity and the WMO accuracy limits for rainfall intensity measurements. It is shown that suitably post-processed weighing gauges and tipping-bucket rain gauges had acceptable performance, while none of the non-catching rain gauges agreed well with the reference.

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Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽

10.32964/tj18.2.93 ◽

2019 ◽

Vol 18 (2) ◽

pp. 93-99

Author(s):

SEYYED MOHAMMAD HASHEMI NAJAFI ◽

DOUGLAS BOUSFIELD, ◽

MEHDI TAJVIDI

Keyword(s):

Mechanical Properties ◽

Double Layer ◽

Starch Content ◽

Single Layer ◽

Double Layers ◽

Coated Paper ◽

Coated Papers ◽

Coating Layers ◽

Scanned Images ◽

Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

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Single Layer Versus Double Layer Closure of Uterus during Caesarean Section – A Prospective Study in Index and Subsequent Pregnancy

International Archives of BioMedical and Clinical Research ◽

10.21276/iabcr.2017.3.1.14 ◽

2017 ◽

Vol 3 (1) ◽

Author(s):

Monika Jindal ◽

Monika Gupta ◽

SPS Goraya ◽

Tanjeet Tanjeet ◽

Prithpal S Matreja

Keyword(s):

Caesarean Section ◽

Prospective Study ◽

Double Layer ◽

Single Layer ◽

Subsequent Pregnancy ◽

Layer Versus ◽

A Prospective Study

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Features of accumulation of amounts of measurement error

Geodesy and Cartography ◽

10.22389/0016-7126-2017-928-10-58-63 ◽

2017 ◽

Vol 928 (10) ◽

pp. 58-63 ◽

Cited By ~ 1

Author(s):

V.I. Salnikov

Keyword(s):

Measurement Error ◽

Confidence Interval ◽

Normal Distribution ◽

Confidence Level ◽

Measurement Errors ◽

Truncated Normal Distribution ◽

Truncated Normal ◽

The Law ◽

Normal Law

The initial subject for study are consistent sums of the measurement errors. It is assumed that the latter are subject to the normal law, but with the limitation on the value of the marginal error Δpred = 2m. It is known that each amount ni corresponding to a confidence interval, which provides the value of the sum, is equal to zero. The paradox is that the probability of such an event is zero; therefore, it is impossible to determine the value ni of where the sum becomes zero. The article proposes to consider the event consisting in the fact that some amount of error will change value within 2m limits with a confidence level of 0,954. Within the group all the sums have a limit error. These tolerances are proposed to use for the discrepancies in geodesy instead of 2m*SQL(ni). The concept of “the law of the truncated normal distribution with Δpred = 2m” is suggested to be introduced.

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