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98MANAL574 Rev. F
INSTALLATION REQUIREMENTS AND CAUTIONS
1. All electrical and pressure connections should be compatible with the above specifications.
2. The Model 574 is susceptible to sensor damage by being dropped, struck, or installed in a high vibration
environment.
3. Installation should occur only after electrical (input power) and line pressure is verified as being off and at zero.
4. The product’s internal electrical circuitry is isolated from case ground. It is not recommended that the case or
ground of the unit be connected to the input or output of the product or wiring system. Ground loops and line
noise will affect the product’s performance and may cause internal electrical failure.
5. Due to the effects of gravity on oil fill of the sensor, it is recommended that the product be mounted as shown
above. If the product is mounted on its side (pressure port facing up) the effect of gravity will show as drift or
product instability
6. Small amounts of vacuum will not damage the product. If a high vacuum is desired, both pressure ports must be
equally drawn down at the same time.
7. The pressure flanges are removable to facilitate cleaning of the pressure cavities. Care should be taken not to
damage diaphragms when flanges are removed. When reassembled, the bolts should be torqued in a criss-
cross pattern; for process flanges with 7/16 x 20 nuts & bolts to 22.0 ft. lbs. or for standard flanges with 5/16 x 24
nuts & bolts to 11.5 ft. lbs.
8. Process media and cleaning solution should be compatible with 316 SS, Viton O-Ring.
9. All products should be protected from direct or continued exposure to fluids at the electrical connection. The
electrical connections on the Model 574 have been designed to be terminated in a junction box or encased in
conduit. In applications where moisture or fluid contamination is possible, the use of a NEMA rated connection
box is recommended for connection termination.
10. At no time should an object be inserted into the pressure port or pressed against the sensing area to deflect the
sensor (to test or simulate pressure) as permanent fill loss and/or damage to the sensing diaphragm may occur.
11. During installation it is recommended that the unit be mounted to allow fluids or contamination to flow away from
the module screw area, so as not to collect on the screw heads or sockets. (Do not mount the unit facing up.)
12. When shipped in quantities, units should be packaged individually to eliminate possible damage.
13. To preserve the integrity of the hermetic design, the units have no field replaceable or repairable parts.
BASIC OPERATION & INTERNAL CALIBRATION CIRCUIT
(See Maintenance and Repair for calibration frequency recommendations.)
Note:
The casting of the module has raised numbers at the adjustment screw positions. Those numbers reflect
the following function of the assigned screw.
Screw 1: Top Left, Coarse Zero Pot (CCW - Lower, CW - Raise)
Screw 2: Top Right, Fine Zero Pot (CCW - Lower, CW - Raise)
Screw 3: Lower Left, Internal Cal. Activation Pot (12 or 6 o’clock position – Disengage; 3 o’clock position - Engage)
Screw 4: Lower Right, Span Adjustment Pot (CCW - Lower, CW - Raise)
1. Outside of using the calibration circuit or the availability of a metrology lab for obtaining a pressure (Full Scale)
reading, no object should be used to physically move the sensor.
2. Once proper connections and power are applied, the unit should begin to function.
3. Check the zero output (4.00 mA) with the performance certificate to verify readings. If it is out of specification
from the performance certificate, use the coarse and fine zero adjustment screws to obtain the proper reading.
4. With no pressure applied, engage the calibration circuit by slowly rotating the calibration screw until the current
output rises to about 8.80 mA’s (standard calibrated range). Check the reading with the performance certificate.
If the reading is off, adjust the span screw to raise or lower the reading – return the calibration circuit to the
original position.
5. When making zero and/or span adjustments, there may be some interaction between the zero and span
readings - repeat adjustments if needed.
6. Always return the calibration screw to off or full CCW position before installing the transmitter into the application.
Note: This is a common reason for incorrect readings at start-up. The calibration circuit must be deactivated in
order for the product to perform properly.
7. Once the product has been tested and functionality verified, the power and meter connections may be removed
and the product reconnected to the instrumentation loop.
NON-STANDARD RANGE (NSR) CALIBRATION
Definition
NSR: A non-standard range is a alternate scaled reading requested by the customer. Through the use of a single
transmitter, numerous pressure ranges can be set-up. The Model 574 can be scaled down to any pressure range to
five times the original range. Only NSR requests for ranges less than the sensor rated range are recommended and
in most cases possible. The NSR is possible due to the ability of the adjustment screws to alter where the zero and
span will fall. Refer to the below example for field NSR calibration.
