Reference Manual

00809-0100-4697, Rev EA October 2011

Rosemount 848T

Table 3-20. Validation Config Sub-Parameter Structure

Validation Value Sub-Parameter

 

Structure

 

Parameter

Description

 

Activates the measurement validation data gathering

VALIDATION_MODE

process

0 = Disable

 

 

1 = Enable

 

Number of seconds per sample used for measurement

SAMPLE_RATE

validation data collection. This shouldn't exceed 10 seconds

 

per sample, but currently there are no upper limits.

DEVIATION_LIMIT

Sets the limit for the deviation diagnostic. DD limits the upper

range to 10.

 

DEVIATION_ENG_UNITS

Units tied to the deviation output value

 

Advisory, Maintenance, Failure

 

0 = Disabled = Does not use the limits, but provides an

 

output

 

1 = Advisory = No effect on sensor status, sets advisory

DEVIATION_ALERT_SEVERITY

PWA

 

2 = Maint = Sets sensor status to uncertain, sets

 

advisory PWA

 

3 = Failure = Sets sensor status to Bad, sets advisory

 

PWA

DEVIATION_PCNT_LIM_HYST

Deviation Hysteresis Limit = (1 -

DEVIATION_PCNT_LIM_HYST/100) * DEVIATION_LIMIT

RATE_INCREASING_LIMIT

Increasing Rate of Change limit set point

RATE_DECREASING_LIMIT

Decreasing Rate of Change limit set point

RATE_ENG_UNITS

Units tied to the rate of change output value

 

Advisory, Maintenance, Failure

 

0 = Disabled = Does not use the limits, but provides an

 

output

 

1 = Advisory = No effect on sensor status, sets advisory

RATE_ALERT_SEVERITY

PWA

 

2 = Maint = Sets sensor status to uncertain, sets

 

advisory PWA

 

3 = Failure = Sets sensor status to Bad, sets advisory

 

PWA

 

Rate of Change Increasing Hysteresis Limit = (1 -

RATE_PCNT_LIM_HYST

RATE_PCNT_LIM_HYST/100) *

 

RATE_INCREASING_LIMIT

 

 

Sensor Calibration in the Sensor Transducer Block

If the FOUNDATION fieldbus configuration tool or host system does not support the use of DD methods for device configuration, the following steps illustrate how to calibrate the sensor from the sensor transducer block:

NOTE:

Active calibrators should not be used in conduction with RTDs on any multiple input temperature transmitter such as the 848T.

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Emerson 848T manual Validation Config Sub-Parameter Structure, Sensor Calibration in the Sensor Transducer Block

848T specifications

The Emerson 848T is a state-of-the-art temperature transmitter designed for accurate and reliable temperature measurement in various industrial applications. This device has gained recognition for its advanced features and robust performance, making it a popular choice among engineers and technicians in the field.

One of the key highlights of the Emerson 848T is its unique dual-channel capability, which allows it to seamlessly monitor two temperature sources simultaneously. This functionality is particularly beneficial in processes where multiple temperature points need to be assessed, optimizing efficiency and reducing the need for additional equipment. It supports various sensor types, including thermocouples, RTDs, and resistance temperature detectors, making it versatile for different applications.

The 848T is equipped with sophisticated digital processing technology, which enhances its accuracy and stability. It features a 24-bit analog-to-digital converter, ensuring precise measurement and minimizing drift over time. Moreover, the device boasts a wide operating temperature range, accommodating ambient conditions from -40°C to 85°C. This durability makes it suitable for harsh environments commonly encountered in industries such as oil and gas, pharmaceuticals, and power generation.

Another significant characteristic of the Emerson 848T is its configurable output options. Users can choose from a range of output signals, including 4-20 mA, which provides a standard interface for integration into existing control systems. Additionally, it offers a HART communication protocol, allowing for easy configuration, calibration, and diagnostics through a digital interface. This feature enhances the transmitter's usability, enabling operators to perform adjustments without direct access to the device.

The device is designed with user-friendliness in mind. Its intuitive setup procedure and robust graphical user interface simplify the commissioning process, ensuring that even those new to the technology can easily navigate the system. An integrated LCD display provides real-time readings and status information, facilitating monitoring at a glance.

In summary, the Emerson 848T temperature transmitter combines reliable performance, user-friendly design, and advanced digital technologies. Its dual-channel capability, wide sensor compatibility, and adjustable output options make it an essential tool for achieving precise temperature measurements in various industrial settings. With these compelling features, the Emerson 848T stands out as a leading choice for professionals seeking accuracy and efficiency in their temperature monitoring applications.