Verify Detector Accuracy - Emerson Rosemount 625IR Manual

Manual
MS-00809-0100-3625
If the response is more than 20 percent FS, the detector has passed the test.
3.1.4 Perform a function check of the Rosemount 625IR Duct
with the gas flush test kit
To perform a function check of the 625IR Duct, the operator can use either the 625IR Duct
gas flush test kit or the 625IR Duct gas bump test kit.
Due to the long sensor section, the bump test can be time-consuming and require a lot of
test gas. An alternative is to use the gas flush test kit.
Prerequisites
• 625IR Duct gas test kit
• Gas cylinder with the same type of gas the detector is rated to detect
—
—
• Flexible gas hose
Procedure
1. Connect the tube from the gas cylinder to the gas nozzle of the gas test kit.
2. Apply the gas from the gas cylinder with a flow rate of at least three liters/minute.
3. Observe whether or not the detector indicator is showing a gas alarm or if a gas
If the response is more than 20% FS, the gas detector has passed the test.
Related information
Perform a function check with the gas test kit
3.2

Verify detector accuracy

Emerson has calibrated the Rosemount 625IR and 625IR Duct for life at the factory. They
do not need to be re-calibrated. At the factory, Emerson has taken great care to account
for environmental effects, such as gas concentration, gas temperature, ambient pressure,
and humidity, to calibrate very precisely. In the field, it is very difficult to account for such
factors, so calibrating the detector in the field would not improve its accuracy.
Prerequisites
• Gas sample kit
• Gas cylinder with calibrated test gas
—
—
• Flexible gas tube between gas cylinder and gas sample kit
Procedure
1. Power up the detector and allow it to warm up for at least 20 minutes.
2. Insert gas test kit.
3. Connect the tube from the gas cylinder to one of the nozzles on the gas test kit.
Rosemount 625IR
This may take several minutes depending on the gas flow and the length of the pipe.
Concentration of test gas recommended to 80% ±10% full scale (FS)
Flow rate of three liters/minute minimum
response is received at the control system.
Concentration of test gas recommended to 50% ±10% full scale (FS)
Flow rate between 0.5 and 1.1 liters/minute
Operation
January 2024
31