Greystone CR3 Series Cleanroom Monitor
Field Calibration Manual
This document describes the procedure for field calibration of the CR3 sensor family. Sensor calibration is not possible in the field; the product offers offsets for both temperature and humidity to adjust readings when verified against a calibrated reference. For differential pressure readings, the product provides an auto-zero option for the CR3A or CR3B models only. Temperature offset can be adjusted in two ways. For CR3XXXBAC and CR3XXXMOD models with communication features, the temperature offset can be set using the protocol documentation. For CR3XXXANA models, the temperature offset can be adjusted via the INSTALLER menu. To perform the offset, use a calibrated reference near the CR3 sensor and adjust the offset on the CR3 sensor to match the reading on the calibrated reference. Temperature offset is adjusted using Analog Input Object Identifier AV1, Object Name: TEMP Offset. The temperature reading can be offset by -5.0 to 5.0 °C or -10 to 10 °F. The default for the AV1 object is 0 °C/°F. Analog Value Object (Present Value defaults to 0 for no offset. Can be set from -10 to +10 °F or -5.0 to +5.0 °C) Temperature Offset (Units depend on the device units, either °C or °F), (°C resolution = 0.5, °F resolution = 1) Temperature offset is adjusted using ModBus address 40018. See reference below. To adjust the temperature offset on these models, use a calibrated reference near the CR3 sensor. Adjust the offset on the CR3 sensor to match the reading on the calibrated reference. Record the difference between the CR3 sensor and the calibrated source, then calculate the required offset for the CR3 sensor's temperature reading to match the calibrated source. The temperature offset can be adjusted via the INSTALLER menu. Access the Installer Menu by pressing and holding the Press and release the Using the Humidity offset can be adjusted in two ways. For CR3XXXBAC and CR3XXXMOD models with communication features, the humidity offset can be set using the protocol documentation. For CR3XXXANA models, the humidity offset can be adjusted via the INSTALLER menu. To perform the offset, use a calibrated reference near the CR3 sensor and adjust the offset on the CR3 sensor to match the reading on the calibrated reference. Humidity offset is adjusted using Analog Input Object Identifier AV2, Object Name: RH Offset. The humidity reading can be offset by -10 to 10 %RH. The default for the AV2 object is 0 %RH. Analog Value Object (Present Value defaults to 0 for no offset. Can be set from -10 to +10 %RH, resolution = 1%) RH Offset Humidity offset is adjusted using ModBus address 40019. See reference below. To adjust the humidity offset on these models, use a calibrated reference near the CR3 sensor. Adjust the offset on the CR3 sensor to match the reading on the calibrated reference. Record the difference between the CR3 sensor and the calibrated source, then calculate the required offset for the CR3 sensor's humidity reading to match the calibrated source. The humidity offset can be adjusted via the INSTALLER menu. Access the Installer Menu by pressing and holding the Press and release the Using the Pressure Auto Zero can be adjusted in two ways. For CR3XXXBAC and CR3XXXMOD models with communication features, the auto-zero can be performed using the protocol documentation. For CR3XXXANA models, the auto-zero can be set via the INSTALLER menu. To perform the auto-zero, the differential pressure between the two zones should ideally be zero. For the auto-zero feature to work, the difference must be within 10% of full scale. Auto Zero is run using Analog Input Object Identifier BV3, Object Name: DP Auto Zero. Binary Value Object (Present Value defaults to 0 (INACTIVE) for Normal Operation. Set to 1 (ACTIVE) to initiate an auto-zero of the pressure sensor) DP Auto Zero This object is disabled for Type C models with remote transmitters. Rules are enforced: Only perform auto-zero function if DP is within ± 0 - 10% of range. DP Auto Zero is run using ModBus address 40051. See reference below. For all models, the DP Auto Zero can be performed via the INSTALLER menu. Access the Installer Menu by pressing and holding the Press and release the When ready to perform the Auto Zero, press and release the Continue to press and release theTemperature Offset
CR3XXXBAC Models
Property Default Value Property Data Type Access Object Identifier AV1 (Analog Value 1) BACnetObjectIdentifier Read Object Name Temperature Offset CharacterString (32) Read Object Type ANALOG_VALUE (2) BACnetObjectType Read Present Value 0 Real Read / Write Description Temperature Offset CharacterString (32) Read Status Flags {false, false, false, false} (0000) BACnetStatusFlags Read Event State NORMAL (0) BACnetEventState Read Out of Service FALSE (0) Boolean Read Units delta-degrees-Fahrenheit (120) or °C (121) BACnetEngineeringUnits Read Property List BACnetArray Read CR3XXXMOD Models
Modbus Address Typical Offset Units Data Type Access Notes 40018 +17 °C / °F Word Read Write 16-bit integer, Temperature Offset -5 to 5 °C, -10 to 10 °F CR3XXXANA Models
Relative Humidity Offset
CR3XXXBAC Models
Property Default Value Property Data Type Access Object Identifier AV2 (Analog Value 2) BACnetObjectIdentifier Read Object Name RH Offset CharacterString (32) Read Object Type ANALOG_VALUE (2) BACnetObjectType Read Present Value 0 Real Read / Write Description RH Offset CharacterString (32) Read Status Flags {false, false, false, false} (0000) BACnetStatusFlags Read Event State NORMAL (0) BACnetEventState Read Out of Service FALSE (0) Boolean Read Units percent-relative-humidity (29) BACnetEngineeringUnits Read Property List BACnetArray Read CR3XXXMOD Models
Modbus Address Typical Offset Units Data Type Access Notes 40019 +18 %RH Word Read Write 16-bit integer, RH Offset -10 to 10 for -10 to 10 %RH CR3XXXANA Models
Differential Pressure Auto Zero
CR3XXXBAC Models
Property Default Value Property Data Type Access Object Identifier BV3 (Binary Value 3) BACnetObjectIdentifier Read Object Name DP Auto Zero CharacterString (32) Read Object Type BINARY_VALUE (5) BACnetObjectType Read Present Value INACTIVE (0) BACnetBinaryPV Read / Write Description Normal (0) or Do Auto Zero (1) CharacterString (32) Read Status Flags {false, false, false, false} (0000) or (1100) if no sensor BACnetStatusFlags Read Event State NORMAL (0) or FAULT (1) if no sensor BACnetEventState Read Reliability NO_FAULT_DETECTED (0) or NO_SENSOR (1) BACnetReliability Read Out of Service FALSE (0) Boolean Read Property List BACnetArray Read CR3XXXMOD Models
Modbus Address Typical Offset Units Data Type Access Notes 40051 +50 %RH Word Read Write 16-bit integer, DP Auto Zero 0 = Normal Operation, 1 = Perform Auto Zero Installer Menu Auto Zero Calibration
