High-Precision Humidity Sensor Response Time Measurement Based on the Switchable Chamber With the Hydrophobic Interface

UV sensors were tested to evaluate the response and reliability as a flameout detection system to reduce system level risks. In this study, UV sensors from two manufacturers were tested on high pressure experimental rigs and on a 15MW gas turbine engine with annular diffusion flame combustion system. Tests were run to investigate the effect of fuel composition, engine load, and sensor circumferential position. The effect of each variable on sensor signal strength and response time is presented in this paper. The response time of the sensor is evaluated against the rate of change of combustor pressure and the time for fuel-air mixture to reach lean extinction limit in the primary zone. Results show that the UV sensor response is not affected by engine load, circumferential location of the sensors, or fuel composition down to Wobbe index of 18.7 MJ/Sm3. At lower Wobbe indices, the signal strength decreased significantly. This result has been attributed to the movement of flame location away from the line of sight of the sensor. Furthermore, it was found that the UV sensor responded before the bulk average reactant mixture reached lean blow out fuel-air ratios. When compared to the baseline detection system the UV sensor performs faster at low load conditions (800 milliseconds) but slower at full load conditions (400 milliseconds). Experimental rig testing led to similar conclusions for sensor response time and signal strength. Future testing of UV sensors on hydrogen blends is planned.

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Evaluation of radiosonde humidity sensors at low temperature using ultralow-temperature humidity chamber

Advances in Science and Research ◽

10.5194/asr-15-207-2018 ◽

2018 ◽

Vol 15 ◽

pp. 207-212 ◽

Cited By ~ 5

Author(s):

Byung Il Choi ◽

Sang-Wook Lee ◽

Sang-Bong Woo ◽

Jong Chul Kim ◽

Yong-Gyoo Kim ◽

...

Keyword(s):

Water Vapor ◽

Low Temperature ◽

Response Time ◽

Humidity Sensor ◽

Weather Prediction ◽

Observation Data ◽

Humidity Sensors ◽

Ultralow Temperature ◽

Humidity Chamber ◽

Sensing Characteristics

Abstract. Accurate measurements of temperature and water vapor in the upper-air are of great interest in relation to weather prediction and climate change. Those measurements are mostly conducted using radiosondes equipped with a variety of sensors that are flown by a balloon up to lower stratosphere. Reference Upper Air Network (GRUAN) has identified water vapor pressure as one of the most important measurands and has set an accuracy requirement of 2 % in terms of the mixing ratio. In order to achieve the requirement, many errors in the humidity measurement such as a temperature dependency in sensing characteristics including measurement values and response time need to be corrected because humidity sensors of radiosondes pass through low-pressure (1 kPa) and low-temperature (−80 ∘C) environments in the upper-air. In this paper, the humidity sensing characteristics of Jinyang radiosonde sensors in relation to temperature dependencies were evaluated at low temperature using a newly developed ultralow-temperature humidity chamber. The sensitivity characteristic curve of the radiosonde sensors was evaluated down to −80 ∘C, and the calibration curves of the humidity sensor and the temperature sensor were obtained. The response time of humidity sensor slowly increased from 52 to 116 s at the temperature from 20 to −40 ∘C, respectively, and then rapidly increased to almost one hour at −80 ∘C. Those results will help to improve the reliability of the upper-air observation data.

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Method of Measuring the Switching Time of Dual Redundant NIC

Global Applications of Pervasive and Ubiquitous Computing ◽

10.4018/978-1-4666-2645-4.ch025 ◽

2013 ◽

pp. 230-235

Author(s):

Zhengrong Tao ◽

Zhenxing Yin

Keyword(s):

High Precision ◽

Switching Time ◽

Time Measurement ◽

Internet Control ◽

Control Message

In this paper, the authors present a method of measuring the switching time of a dual redundant NIC. The accuracy of the authors’ method of measuring switching time can reach milliseconds. The authors’ method uses Internet Control Message Protocol (ICMP) packets to test, is easy to operate, has high precision, and can be applied to all types of dual redundant device switching time measurement.

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Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring

Biosensors ◽

10.3390/bios9020060 ◽

2019 ◽

Vol 9 (2) ◽

pp. 60 ◽

Cited By ~ 15

Author(s):

Uswatun Hasanah ◽

Mita Setyowati ◽

Rustam Efendi ◽

Muslem Muslem ◽

Nor Diyana Md Sani ◽

...

Keyword(s):

Standard Deviation ◽

Response Time ◽

Relative Standard Deviation ◽

Ph Sensor ◽

Sensor Response ◽

Relative Standard ◽

Optical Ph Sensor

In a simple and instant procedure for detecting fish freshness, a hydrogel and hydrophilic pectin matrix membrane was used successfully as an optical pH sensor by immobilizing the chromoionophore ETH 5294 (CI), which is very selective and sensitive for the membrane. The Pe/CI optical pH sensor exhibited excellent linearity between pH 5 and pH 9, with a sensor response time of 5 min and reproducibility of 1.49% relative standard deviation (RSD). The sensor showed response stability for 15 days and a response reduction of 8.6%. The sensor’s capability was demonstrated by the detection of fish freshness for 17 days at 4 °C.

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