Set-up – American Magnetics 175 Industrial Level Transmitter (CE-Marked) User Manual

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SECTION B

This section contains the Operation and Maintenance instructions for the American Magnetics,
Inc. Model 175 Two-Wire Continuous Level Transmitter. Since it is impossible to cover all
possible sensor/systems configurations, only the most common are discussed in this document.
The user is encouraged to contact an authorized American Magnetics Instrument Technical
Support Representative for specific situations.

Set-up details the software commands and procedures for matching (calibrating) the transmitter
to your particular application.

Troubleshooting provides information and various tests used to determine the cause of any
issues with the Model 175 transmitter.

Set-Up

The Model 175 Transmitter displays information locally in a 2-line by 8-character format. The
normal operating display can be set to either LEVEL & %OUTPUT, or LEVEL & LOOP
CURRENT. The keypad consists of three buttons. “Up” and “Down” are used to scroll through
the menu or change the numeric value of a particular option. Depress either of the buttons
continuously to rapidly change the numeric value. “Enter” is used to accept the data that has
been selected with the “Up” and “Down” buttons.

The buttons can be actuated through the glass window in the cover, using the supplied Magnet
Tool. It is not necessary to remove the cover to set-up this transmitter.

ProxCal™ Calculation

This method is the least accurate form of calibration and should be used only when it is impossible to
change the level of the process fluid. This method requires a substitute low dielectric, low conductivity
fluid to be used for calibration. A cryogenic or stilling well probe must be used if the actual process vessel
is not available for the calibration process.

To use ProxCal, the level measurements used for Probe LO and Probe HI must be referenced from the
tip of the probe (probe bottom). In other words the probe bottom must be considered zero (inches or
mm).

The dielectric constant for the reference (substitute) fluid

, and the target (process) fluid

are needed

for the ProxCal factor calculation. The equation is as follows:

Install the transmitter into the target vessel containing the process fluid. Go to the “Menu Structure”
section for directions on how to enter the ProxCal factor into the transmitter.

If you do not know the dielectric constant of the fluids, obtain the actual level of the process fluid in the
target vessel. Install the transmitter into the target vessel. Adjust the ProxCal factor until the transmitter
displays the level in the vessel obtained previously.

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ProxCal Factor