Differences
This shows you the differences between two versions of the page.
| Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
| resources:eval:user-guides:eval-adicup360:hardware:cn0411 [26 Jul 2018 03:24] – created Angelo Nikko Catapang | resources:eval:user-guides:eval-adicup360:hardware:cn0411 [30 Jul 2021 07:43] (current) – [Registration] Zuedmar Arceo | ||
|---|---|---|---|
| Line 1: | Line 1: | ||
| - | ====== EVAL-CN0411-ARDZ Shield Overview ====== | + | ======EVAL-CN0411-ARDZ Shield Overview====== |
| + | [[ADI> | ||
| + | [[ADI> | ||
| + | The range of conductivity measurement can be adjusted using gain resistors switched using the [[ADI> | ||
| + | The conductivity cell signal is measured by the [[ADI> | ||
| + | This design uses a combination of components that allow for single supply operation which minimize circuit complexity, making this suitable for low-power and portable instrument applications. Applications include chemical water analysis for field research, and monitoring water systems and natural bodies of water.\\ | ||
| + | \\ | ||
| + | {{ : | ||
| + | =====Total Dissolved Solids Measurement===== | ||
| + | The measurement of the total dissolved solids in a solution relies primarily on the conductivity and the temperature of the solution. Furthermore, | ||
| + | ====Hardware Connection and Jumper Configurations==== | ||
| + | The [[ADI> | ||
| + | {{ : | ||
| + | ===Sensor Connections=== | ||
| + | The CN-0411 has three hardware connectors which have no polarity and can connect directly to the sensors:\\ \\ | ||
| + | J1 is for 2-wire conductivity probes with a BNC plug. This is compatible with common commercial probes. Below are recommended probes of different cell constants.\\ | ||
| + | ^ Cell Constant | ||
| + | | 0.1 | CS SK21T 2-Electrode Glass Cell | {{ : | ||
| + | | 1 | CS SK20T 2-Electrode Glass Cell | {{ : | ||
| + | | 10 | ||
| + | P2 is a terminal block connector for conductivity probe' | ||
| + | {{ : | ||
| + | P3 is a terminal block connector for a 2-wire RTD. The software is compatible with Pt100 and Pt1000 RTDs. The connection diagram is shown below\\ | ||
| + | {{ : | ||
| + | ===Jumper Configurations=== | ||
| + | The [[ADI> | ||
| + | {{ : | ||
| + | ===Sensor Select=== | ||
| + | PRB_SEL selects the connection to the conductivity sensor. By default, the shunt is placed connecting pin 1 and 2 to measure the conductivity of the solution.\\ | ||
| + | ^ PRB_SEL Shunt Position | ||
| + | | 1 and 2 | ||
| + | | 3 and 4 | ||
| + | | 5 and 6 | ||
| + | * Connecting Pins 1 and 2 allows the system to measure the conductivity of the solution. | ||
| + | * Connecting Pins 3 and 4 allows the system to calibrate in the 0.01 S range | ||
| + | * Connecting Pins 5 and 6 allows the system to calibrate in the 0.1 S range | ||
| + | ===Signal Input Select=== | ||
| + | P6 selects selects the input to the [[ADI> | ||
| + | ^ P6 Shunt Position | ||
| + | | 1 and 2 | Conductivity Signal | ||
| + | | 2 and 3 | AGND | | ||
| + | * By connecting Pins 1 and 2, the [[ADI> | ||
| + | * Connecting Pins 2 and 3 allows the system to perform zero-scale calibration of the system. | ||
| + | ===ADC Chip Select=== | ||
| + | CS_ADC selects the chip select GPIO pin for the [[ADI> | ||
| + | ^ CS_ADC Shunt Position | ||
| + | | 1 and 2 | DIGI1 Pin 1 or GPIO28 | ||
| + | | 3 and 4 | DIGI1 Pin 2 or GPIO30 | ||
| + | ===DAC Chip Select=== | ||
| + | CS_DAC selects the chip select GPIO pin for the [[ADI> | ||
| + | ^ CS_DAC Shunt Position | ||
| + | | 1 and 2 | DIGI1 Pin 3 or GPIO26 | ||
| + | | 3 and 4 | DIGI0 Pin 3 or GPIO15 | ||
| + | ====Conductivity Measurement==== | ||
| + | The system measures conductivity using a 2-wire conductivity probe to be immersed in the solution as shown below.\\ | ||
| + | {{ : | ||
| + | It is preferable that the conductivity probe be positioned at the center of the container to maximize the accuracy of the measurement. The cell constant of a 2-wire conductivity probe is the distance between its two cells or electrodes divided by their inner surface area. The cell constant of the conductivity probe sets the range of conductivity measurements it is suitable to use. Proper selection of the probe makes it easier for the system to measure at a certain conductivity range. Below is the table listing the range of conductivity measurements appropriate for the probe' | ||
| + | ^ Cell Constant | ||
| + | | 0.01 | ||
| + | | 0.1 | 0.1 μS/cm to 100 μS/ | ||
| + | | 1 | 100 μS/cm to 10 mS/cm | | ||
| + | | 10 | ||
| + | <note important> | ||
| + | The frequency of the excitation signal across the conductivity cells depends on the range of conductivity measurement. The system can switch between 94 Hz, suitable for measurements in the μS range, and 2.4kHz suitable for measurements in the mS range and above. | ||
| + | ====Temperature Measurement==== | ||
| + | The system can use either Pt100 or Pt1000 RTD sensors and is configurable through the software. Most commercial probes in the market have these RTDs built in the conductivity probe.\\ | ||
| + | The temperature coefficient depends on the type of solution and can be configured in the software. The system has built-in stored values for sodium chloride (NaCl) and potassium chloride (KCl) solutions as shown in the table below.\\ | ||
| + | ^ Salt Solution | ||
| + | | Potassium Chloride (KCl) | 1.88 | | ||
| + | | Sodium Chloride (NaCl) | ||
| + | ====Total Dissolved Solids Measurement==== | ||
| + | The total dissolved solids in the solution is computed from the temperature-compensated conductivity measurement by the TDS factor which varies per type of dissolved solid. This can be configured through software and the system has built-in stored values for NaCl and KCl solutions.\\ | ||
| + | ^ Salt Solution | ||
| + | | Potassium Chloride (KCl) | 0.50 to 0.57 | | ||
| + | | Sodium Chloride (NaCl) | ||
| + | ====Calibration and Auto-ranging==== | ||
| + | The system can automatically select the proper gain resistance from the user-defined excitation voltage when commanding the system to measure TDS. Below is the procedure used to select the gain resistance appropriate to the measured conductivity range.\\ | ||
| + | {{ : | ||
| + | To decrease the effect of system noise to the measurement, | ||
| + | - Place the shunt position of jumper header P6 to connect pins 2 and 3. | ||
| + | - Command the software to perform zero-scale calibration. | ||
| + | - Wait for the command to finish | ||
| + | - Place the shunt position of the jumper header P6 back to pins 1 and 2\\ \\ | ||
| + | To increase the accuracy of the system in the 0.01 S range or 0.1 S range, reference-resistor calibration should be performed once per board. This calibrates the system to a known 200 Ω and 20 Ω precision resistance, respectively. Below are the steps to perform reference-resistor calibration. | ||
| + | - Place the shunt position of PRB_SEL to connect pins 3 and 4 for a 0.01 S range calibration or to connect pins 5 and 6 for a 0.1 S range calibration. | ||
| + | - Command the software to perform a reference resistor calibration | ||
| + | - Wait for the command to finish | ||
| + | - Place the shunt position of the jumper header PRB_SEL back to pins 1 and 2\\ | ||
| + | ===== Software ===== | ||
| + | |||
| + | * [[/ | ||
| + | ===== Schematic, PCB Layout, Bill of Materials ===== | ||
| + | <WRAP round 80% download> | ||
| + | |||
| + | [[adi> | ||
| + | \\ | ||
| + | * Schematics | ||
| + | * PCB Layout | ||
| + | * Bill of Materials | ||
| + | * Allegro Project | ||
| + | </ | ||
| + | |||
| + | =====Registration===== | ||
| + | <WRAP round tip 80% > | ||
| + | Receive software update notifications, | ||
| + | </ | ||
| + | |||
| + | |||
| + | // End of Document // | ||
resources/eval/user-guides/eval-adicup360/hardware/cn0411.1532568294.txt.gz · Last modified: 26 Jul 2018 03:24 by Angelo Nikko Catapang