54-631 Thermatel® Model TA2 Instruction and

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10. Reassemble the bezel and install cover.

11. Reapply power.

12. Proceed to section 4.3

4.3 Replacement Calibration

4.3.1 RTD Calibration

If either the probe or the processor board is replaced in the field, calibration of the RTDs in the probe will return the

TA2 to like-new performance.

NOTE: If this procedure is not followed, the accuracy will be affected; however, very repeatable flow measurements will be obtained.

Locate the sensor vertically in a water bath with an accurate temperature sensor directly adjacent to the probe tips. It is preferable that the water is stirred during the calibration to ensure the TA2 pins and temperature probe are at the same temperature. Using the keypad and display, select

“Factory Config\Probe Params\Probe Temp Calib” and then press the Enter key. The device will dynamically display the To/Fo readings over a period of time. After 3 minutes, and if the readings are stable enough, the display automatically changes to request entry of a password (126) followed by the ambient water temperature. After the temperature is entered, the device will display if the calibration is OK. The device then automatically resets itself for normal operation. A similar procedure exists for the DD and

DTM.

4.3.2 Set Point Adjustment

A new set point must be calculated to complete the reconfiguration.

1. Place the probe in ambient temperature air where there is no flow across the sensor. This can be accomplished by wrapping the sensor tip with a piece of paper.

2. Go into Diagnostics

’ Signal. Allow time for the signal to stabilize to within ±1 mW and record the new signal.

3. Calculate a new set point by using the following formula:

New set point = set point x (zero flow signal ÷ new signal)

If replacing the probe, use the set point and zero flow signal (ZFS) shown on the new calibration certificate that came with the probe.

If replacing the processor board, use the set point and ZFS on the original calibration certificate. If the original calibration certificate is not available, contact MAGNETROL with the serial number of the unit found on the nameplate.

New signal is the value measured under step 2.

54-631 THERMATEL Model TA2 Transmitter