Atlas EZO-EC module

Sensor Datasheet

• Circuit Datasheet
• K0.1 Probe Datasheet
• K1.0 Probe Datasheet
• K10 Probe Datasheet

Sensor Constructors

Example Code

The Atlas conductivity sensor is used in the menu a la carte example.

#include <sensors/AtlasScientificEC.h>

// NOTE: Use -1 for any pins that don't apply or aren't being used.
const int8_t AtlasECPower    = sensorPowerPin;  // Power pin
uint8_t      AtlasECi2c_addr = 0x64;            // Default for EC is 0x64 (100)
// All Atlas sensors have different default I2C addresses, but any of them can
// be re-addressed to any 8 bit number.  If using the default address for any
// Atlas Scientific sensor, you may omit this argument.

// Create an Atlas Scientific Conductivity sensor object
// AtlasScientificEC atlasEC(AtlasECPower, AtlasECi2c_addr);
AtlasScientificEC atlasEC(AtlasECPower);

// Create four variable pointers for the EZO-ES
Variable* atlasCond = new AtlasScientificEC_Cond(
    &atlasEC, "12345678-abcd-1234-ef00-1234567890ab");
Variable* atlasTDS =
    new AtlasScientificEC_TDS(&atlasEC, "12345678-abcd-1234-ef00-1234567890ab");
Variable* atlasSal = new AtlasScientificEC_Salinity(
    &atlasEC, "12345678-abcd-1234-ef00-1234567890ab");
Variable* atlasGrav = new AtlasScientificEC_SpecificGravity(
    &atlasEC, "12345678-abcd-1234-ef00-1234567890ab");

// Create a calculated variable for the temperature compensated conductivity
// (that is, the specific conductance).  For this example, we will use the
// temperature measured by the Atlas RTD above this.  You could use the
// temperature returned by any other water temperature sensor if desired.
// **DO NOT** use your logger board temperature (ie, from the DS3231) to
// calculate specific conductance!
float calculateAtlasSpCond(void) {
    float spCond    = -9999;  // Always safest to start with a bad value
    float waterTemp = atlasTemp->getValue();
    float rawCond   = atlasCond->getValue();
    // ^^ Linearized temperature correction coefficient per degrees Celsius.
    // The value of 0.019 comes from measurements reported here:
    // Hayashi M. Temperature-electrical conductivity relation of water for
    // environmental monitoring and geophysical data inversion. Environ Monit
    // Assess. 2004 Aug-Sep;96(1-3):119-28.
    // doi: 10.1023/b:emas.0000031719.83065.68. PMID: 15327152.
    if (waterTemp != -9999 && rawCond != -9999) {
        // make sure both inputs are good
        float temperatureCoef = 0.019;
        spCond = rawCond / (1 + temperatureCoef * (waterTemp - 25.0));
    }
    return spCond;
}

// Properties of the calculated variable
// The number of digits after the decimal place
const uint8_t atlasSpCondResolution = 0;
// This must be a value from http://vocabulary.odm2.org/variablename/
const char* atlasSpCondName = "specificConductance";
// This must be a value from http://vocabulary.odm2.org/units/
const char* atlasSpCondUnit = "microsiemenPerCentimeter";
// A short code for the variable
const char* atlasSpCondCode = "atlasSpCond";
// The (optional) universallly unique identifier
const char* atlasSpCondUUID = "12345678-abcd-1234-ef00-1234567890ab";

// Finally, create the specific conductance variable and return a pointer to it
Variable* atlasSpCond =
    new Variable(calculateAtlasSpCond, atlasSpCondResolution, atlasSpCondName,
                 atlasSpCondUnit, atlasSpCondCode, atlasSpCondUUID);

Classes

class AtlasScientificEC

The Sensor sub-class for the Atlas Scientific conductivity circuit and sensor.

class AtlasScientificEC_Cond

The Variable sub-class used for the conductivity output from an Atlas Scientific EC EZO circuit.

class AtlasScientificEC_TDS

The Variable sub-class used for the total dissolved solids output from an Atlas Scientific EC EZO circuit.

class AtlasScientificEC_Salinity

The Variable sub-class used for the salinity output from an Atlas Scientific EC EZO circuit.

class AtlasScientificEC_SpecificGravity

The Variable sub-class used for the specific gravity output from an Atlas Scientific EC EZO circuit.

Defines

#define ATLAS_COND_I2C_ADDR = 0x64

Default I2C address is 0x64 (100)

#define ATLAS_COND_NUM_VARIABLES = 4

Sensor::_numReturnedValues; Atlas EZO conductivity circuit can report 4 values.

#define ATLAS_COND_INC_CALC_VARIABLES = 0

Sensor::_incCalcValues; we don't calculate any additional values - though we recommend users include a temperature sensor and calculate specific conductance in their own program.

Sensor Timing

The sensor timing for an Atlas EC (conducticity) sensor

#define ATLAS_COND_WARM_UP_TIME_MS = 745

Sensor::_warmUpTime_ms; Atlas EZO conductivity circuit warms up in 745ms.

739-740 in tests

#define ATLAS_COND_STABILIZATION_TIME_MS = 0

Sensor::_stabilizationTime_ms; Atlas EZO conductivity circuit is stable 0ms after warm-up. (stable at completion of warm up)

#define ATLAS_COND_MEASUREMENT_TIME_MS = 600

Sensor::_measurementTime_ms; Atlas EZO conductivity circuit takes 600ms to complete a measurement.

only ~555 measurement time in tests, but keep the 600 recommended by manual

Conductivity

The conductivity variable from an Atlas EC (conducticity) sensor

• Accuracy is ± 2%
• Range is 0.07 − 500,000+ μS/cm

#define ATLAS_COND_RESOLUTION = 3

Decimals places in string representation; conductivity should have 3.

#define ATLAS_COND_VAR_NUM = 0

Sensor variable number; conductivity is stored in sensorValues[0].

#define ATLAS_COND_VAR_NAME = "electricalConductivity"

Variable name in ODM2 controlled vocabulary; "electricalConductivity".

#define ATLAS_COND_UNIT_NAME = "microsiemenPerCentimeter"

Variable unit name in ODM2 controlled vocabulary; "microsiemenPerCentimeter" (µS/cm)

#define ATLAS_COND_DEFAULT_CODE = "AtlasCond"

Default variable short code; "AtlasCond".

Total Dissolved Solids

The TDS variable from an Atlas EC (conducticity) sensor

• Accuracy is ± 2%
• Range is 0.07 − 500,000+ μS/cm

#define ATLAS_TDS_RESOLUTION = 3

Decimals places in string representation; TDS should have 3.

#define ATLAS_TDS_VAR_NUM = 1

Sensor variable number; TDS is stored in sensorValues[1].

#define ATLAS_TDS_VAR_NAME = "solidsTotalDissolved"

Variable name in ODM2 controlled vocabulary; "solidsTotalDissolved".

#define ATLAS_TDS_UNIT_NAME = "partPerMillion"

Variable unit name in ODM2 controlled vocabulary; "partPerMillion" (ppm)

#define ATLAS_TDS_DEFAULT_CODE = "AtlasTDS"

Default variable short code; "AtlasTDS".

Salinity

The salinity variable from an Atlas EC (conducticity) sensor

• Accuracy is ± 2%
• Range is 0.07 − 500,000+ μS/cm

#define ATLAS_SALINITY_RESOLUTION = 3

Decimals places in string representation; salinity should have 3.

#define ATLAS_SALINITY_VAR_NUM = 2

Sensor variable number; salinity is stored in sensorValues[2].

#define ATLAS_SALINITY_VAR_NAME = "salinity"

Variable name in ODM2 controlled vocabulary; "salinity".

#define ATLAS_SALINITY_UNIT_NAME = "practicalSalinityUnit"

Variable unit name in ODM2 controlled vocabulary; "practicalSalinityUnit".

#define ATLAS_SALINITY_DEFAULT_CODE = "AtlasSalinity"

Default variable short code; "AtlasSalinity".

Specific Gravity

The specific gravity variable from an Atlas EC (conducticity) sensor

• Accuracy is ± 2%
• Range is 0.07 − 500,000+ μS/cm

#define ATLAS_SG_RESOLUTION = 3

Decimals places in string representation; specific gravity should have 3.

#define ATLAS_SG_VAR_NUM = 3

Sensor variable number; specific gravity is stored in sensorValues[3].

#define ATLAS_SG_VAR_NAME = "specificGravity"

Variable name in ODM2 controlled vocabulary; "specificGravity".

#define ATLAS_SG_UNIT_NAME = "dimensionless"

Variable unit name in ODM2 controlled vocabulary; "dimensionless".

#define ATLAS_SG_DEFAULT_CODE = "AtlasSpecGravity"

Default variable short code; "AtlasSpecGravity".