A PCB Sensor Suite for Monitoring the Effects of Annual Variations in Precipitation Rates on Alpine Lakes in Rocky Mountain National Park

2017 ◽  
Vol 2017 (DPC) ◽  
pp. 1-22
Author(s):  
Robert Dean ◽  
Isabella A. Oleksy ◽  
Daniel W. Bowker
Keyword(s):  
Low Cost ◽  
Rocky Mountain ◽  
Alpine Lakes ◽  
Rocky Mountain National Park ◽  
Circuit Board ◽  
Annual Variations ◽  
Electrode Sensor ◽  
Fringing Field ◽  
Field Sensor ◽  
Sensor Suite

Alpine Lakes are fragile ecosystems of immense beauty and value. They occur in high elevations and are often subjected to wide variations in annual precipitation rates. As such, their electrochemistry is affected by these annual variations in precipitation rates, which in turn, affects the entire ecosystem. Low-cost sensors for monitoring these changes will help in improving the management of these ecosystems. Low-cost Printed Circuit Board (PCB) sensors are being applied to many useful environmental and agricultural applications, including measuring soil moisture content, detecting pollution, monitoring drought conditions in estuaries, and monitoring for saltwater intrusion into coastal freshwater bodies. These sensors consist of a low-cost PCB with patterned Cu electrodes designed so that the circuit board electromagnetically interacts with the surrounding media, where its electrochemistry affects the measurable electrical impedance of the patterned traces. Exposed electrodes can be used to measure ion content in aqueous solutions from dissolved ionic compounds. Insulated electrodes can be used to measure moisture content of object and materials, or to identify dissolved ions in aqueous solution by searching for their relaxation frequency. In this multiyear study, a 2-layer PCB sensor suite consisting of a Au coated dual exposed electrode sensor on one side and a solder mask insulated interdigitated fringing field sensor on the opposite side is used. SMA connectors are attached to the opposite end of the sensor board for easy connection too instrumentation. The resistance of the exposed electrode sensor is measured using an Agilent 4192A LF Impedance Analyzer. The complex impedance of the fringing field sensor is measured using an Agilent E5061B Network Analyzer. For this study, PCB sensor technology is being investigated for monitoring the electrochemical properties of water samples from four alpine lake ecosystems in the Loch Vale Drainage at Rocky Mountain National Park. These alpine lakes are The Loch, Sky Pond, Andrews Tarn and Lake of Glass. Water samples were collected from these ecosystems in August of 2016, taken into the laboratory and tested with the PCB sensor suite to determine a baseline for the five year study.

A Wireless Hay Bale Status Sensor Suite Using PCB Sensor Technology

2017 ◽  
Vol 2017 (DPC) ◽  
pp. 1-31
Author(s):  
Jeff D. Craven ◽  
Andrew W. Muscha ◽  
R. Chase Harrison ◽  
Markus A. R. Kreitzer ◽  
Robert N. Dean ◽  
...  
Keyword(s):  
Moisture Content ◽  
Spontaneous Combustion ◽  
Thermophilic Bacteria ◽  
Low Cost ◽  
The United States ◽  
Circuit Board ◽  
Sensor Technology ◽  
Moisture Content Level ◽  
Suitable Environment ◽  
Sensor Suite

The spontaneous combustion of curing hay bales poses serious safety and financial issues to farmers and ranchers across the United States and abroad. The primary cause of this spontaneous combustion is the baling of hay before it has adequately dried and reached a sufficiently low moisture content level. This inadequate drying is primarily due to the farmer allowing the hay to dry in the field after cutting for a given period of time. But unfortunately, this does not always ensure that the hay has sufficiently dried before baling. Spontaneous combustion of hay bales is due to a proliferation of thermophilic bacteria that thrive in a moist and hot environment. If the moisture content of hay is greater than 20%, it provides a suitable environment for mesophilic bacteria, which can heat the hay to as a high as 140°F. Although this is not problematic in and of itself, a 140°F hay bale is a suitable environment for the proliferation of thermophilic bacteria, which can further heat the hay to 170oF. At this temperature, the hay can spontaneous combust, destroying the hay and risking the loss of buildings, equipment, livestock and agricultural workers. To combat this problem, a low-cost, low-power, wireless hay bale status sensor suite has been developed so that the farmer can easily and safely monitor the conditions inside a curing hay bale, to give the farmer time to take action before the bale spontaneously combusts. The battery operated sensor suite has two sensors in contact with the hay inside the bale, a printed circuit board (PCB) moisture content sensor and a discrete temperature sensor. The extremely low-cost of the PCB moisture content sensor is what enables the practicality of the sensor suite. WiFi is used to transmit moisture content and temperature data to the farmer's smartphone when it comes within range. The sensor suite is placed inside the bale at the time of baling. After the bale has fully cured, in four to six weeks, the reusable sensor suite can be removed and used in a new bale.

A Capacitive Fringing Field Sensor Design for Moisture Measurement Based on Printed Circuit Board Technology

2012 ◽  
Vol 61 (4) ◽  
pp. 1105-1112 ◽  
Author(s):  
Robert Neal Dean ◽  
Aditi Kiran Rane ◽  
Michael E. Baginski ◽  
Jonathan Richard ◽  
Zane Hartzog ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Sensor Design ◽  
Moisture Measurement ◽  
Printed Circuit ◽  
Fringing Field ◽  
Field Sensor

scholarly journals A Technique for Detecting Moisture Absorption in Printed Circuit Boards

2020 ◽  
Vol 17 (1) ◽  
pp. 28-33
Author(s):  
Jeffery D. Craven ◽  
Ariel R. Oldag ◽  
Robert N. Dean
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Moisture Absorption ◽  
Low Cost ◽  
Circuit Board ◽  
Sensor Technology ◽  
Circuit Boards ◽  
Liquid Form ◽  
Printed Circuit ◽  
Fringing Field

Abstract Most circuit boards operate in environments that have the potential to be exposed to moisture, either in vapor or liquid form. Because low-cost circuit boards can readily absorb moisture, this can lead to performance issues, reliability issues, and even catastrophic failure. However, it is difficult to detect if moisture absorption has occurred before the circuit board suffers a complete failure. To alleviate this issue, a fringing field capacitor was implemented in printed circuit board (PCB) technology and used to detect the absorption of moisture in the circuit board through the accompanying increase in capacitance. Prototype sensors were fabricated and immersed for 42 d, demonstrating an increase in capacitance of between 14% and 29%. This sensor technology can easily be added to circuit board designs because they use the standard materials and fabrication processes used in commercial PCB construction.

A Novel Wideband transition from Substrate Integrated Waveguide to Rectangular Waveguide

2020 ◽  
Vol 10 ◽  
Author(s):  
Keyur Mahant ◽  
Hiren Mewada ◽  
Amit Patel ◽  
Alpesh Vala ◽  
Jitendra Chaudhari
Keyword(s):  
Rectangular Waveguide ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Single Layer ◽  
Circuit Board ◽  
Substrate Integrated Waveguide ◽  
Ka Band ◽  
Better Than ◽  
Millimeter Wave Circuits ◽  
Wideband Transition

Aim: In this article, wideband substrate integrated waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band is proposed Objective: In this article, wideband substrate integrated waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band is proposed. Method: Coupling patch etched on the SIW cavity to couple the electromagnetic energy from SIW to RWG. Moreover, metasurface is introduced into the radiating patch to enhance bandwidth. To verify the functionality of the proposed structure back to back transition is designed and fabricated on a single layer substrate using standard printed circuit board (PCB) fabrication technology. Results: Measured results matches with the simulation results, measured insertion loss is less than 1.2 dB and return loss is better than 3 dB for the frequency range of 28.8 to 36.3 GHz. By fabricating transition with 35 SRRs bandwidth of the proposed transition can be improved. Conclusion: The proposed transition has advantages like compact in size, easy to fabricate, low cost and wide bandwidth. Proposed structure is a good candidate for millimeter wave circuits and systems.

scholarly journals Assessment of High Resolution Air Temperature Fields at Rocky Mountain National Park by Combining Scarce Point Measurements with Elevation and Remote Sensing Data

2020 ◽  
Vol 13 (1) ◽  
pp. 113
Author(s):  
Antonio-Juan Collados-Lara ◽  
Steven R. Fassnacht ◽  
Eulogio Pardo-Igúzquiza ◽  
David Pulido-Velazquez
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Air Temperature ◽  
Land Surface ◽  
National Park ◽  
Rocky Mountain ◽  
Rocky Mountain National Park ◽  
Temperature Fields ◽  
Lapse Rate ◽  
Validation Experiment

There is necessity of considering air temperature to simulate the hydrology and management within water resources systems. In many cases, a big issue is considering the scarcity of data due to poor accessibility and limited funds. This paper proposes a methodology to obtain high resolution air temperature fields by combining scarce point measurements with elevation data and land surface temperature (LST) data from remote sensing. The available station data (SNOTEL stations) are sparse at Rocky Mountain National Park, necessitating the inclusion of correlated and well-sampled variables to assess the spatial variability of air temperature. Different geostatistical approaches and weighted solutions thereof were employed to obtain air temperature fields. These estimates were compared with two relatively direct solutions, the LST (MODIS) and a lapse rate-based interpolation technique. The methodology was evaluated using data from different seasons. The performance of the techniques was assessed through a cross validation experiment. In both cases, the weighted kriging with external drift solution (considering LST and elevation) showed the best results, with a mean squared error of 3.7 and 3.6 °C2 for the application and validation, respectively.

scholarly journals Highly Compact Through-Wire Microstrip to Empty Substrate Integrated Coaxial Line Transition

2021 ◽  
Vol 11 (15) ◽  
pp. 6885
Author(s):  
Marcos D. Fernandez ◽  
José A. Ballesteros ◽  
Angel Belenguer
Keyword(s):  
Printed Circuit Board ◽  
Low Cost ◽  
Coaxial Line ◽  
Circuit Board ◽  
Central Layer ◽  
Printed Circuit ◽  
Integrated Technology ◽  
Low Profile ◽  
The Many ◽  
High Degree

Empty substrate integrated coaxial line (ESICL) technology preserves the many advantages of the substrate integrated technology waveguides, such as low cost, low profile, or integration in a printed circuit board (PCB); in addition, ESICL is non-dispersive and has low radiation. To date, only two transitions have been proposed in the literature that connect the ESICL to classical planar lines such as grounded coplanar and microstrip. In both transitions, the feeding planar lines and the ESICL are built in the same substrate layer and they are based on transformed structures in the planar line, which must be in the central layer of the ESICL. These transitions also combine a lot of metallized and non-metallized parts, which increases the complexity of the manufacturing process. In this work, a new through-wire microstrip-to-ESICL transition is proposed. The feeding lines and the ESICL are implemented in different layers, so that the height of the ESICL can be independently chosen. In addition, it is a highly compact transition that does not require a transformer and can be freely rotated in its plane. This simplicity provides a high degree of versatility in the design phase, where there are only four variables that control the performance of the transition.

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