Laurel Electronics 88-PRO Loop Powered Process Meter - Manual

LAUREL ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
LAUREL
ELECTRONICS, INC.
88-PRO Loop Powered Process Meter
With 0.50" high LCD digits and detachable screw terminals
Features
• Powered by 4-20 mA, 10-50 mA or 1-5 mA loop, with no need for other power
• Maximum 2.5 V voltage drop
• Easy zero & span adjustment from rear of meter
• 3-1/2 digit resolution (±1999)
• Jumper-selectable dummy right-hand zeros for reading to ±19990 or ±199900
• Normal or inverted scaling
• High-legibility 12.7 mm (0.50") digits
• 1/8 DIN panel cutout, only 93 mm (3.66") required behind panel
• Environmental protection to IP54 (NEMA-12) when panel mounted
• High-quality plug-in screw terminals
• Low cost
Description
Loop powered. The 88-PRO Process Meter may be connected
directly to a 4-20 mA, 10-50 mA or 1-5 mA current loop, with no
need for additional power to the meter. This is because the meter
is powered directly by the current loop, developing a maximum
voltage drop of 2.5 V.
Readout in engineering units. By accepting 4-20 mA, 10-50 mA
or 1-5 mA signals, the 88-PRO is compatible with a large number
of industrial transducers and transmitters to display process
variables such as temperature, pressure, flow, weight, pH,
humidity etc. Zero and span are adjustable for direct readout in
engineering units. There is an INVERT facility, so that an
increasing input signal gives a reducing display, for example,
4-20 mA = 100.0 to 0.0. The 88-PRO also provides two jumper-
selectable dummy right-hand zero to extend the maximum
reading from the default of ±1999 to ±19990 or ±199900. This
feature allows the display of large numbers, such as the weight
of a truck in pounds. It also useful when the cost of a 4 ½ or 5 ½
digit meter may be too high
Easy to install and set up. The 88-PRO fits in a standard 1/8
DIN panel cutout and only requires 93 mm (3.66") behind the
panel. This is less than for most process meters. There are only
two signal connections: signal in and signal out. These are made
via a detachable screw terminal connector. All range-selection
jumpers as well as the meter's zero and span adjustments are
from the rear of the meter, avoiding the need to open the case.
Attractive and easy to read. The facia of the 88-PRO is
attractively styled. The simple bezel will compliment your panel
design. The lens protects all legends and markings, so repeated
wipe-downs won't damage the lettering or display clarity. High
contrast LCDs make these meters suitable for use in bright
environments. The digits measure a full 12.7 mm (0.50").
An application example. The 88-PRO loop-powered process
meter is in series with 12-30 Vdc power to a two-wire 4-20 mA
pressure transmitter, which measures the pressure at the bottom
of a straight-sided tank. The meter's broad scaling capabilities
allow it to be adjusted to display the volume of the tank. When
necessary, one or two dummy right hand zeros may be added to
display values up to 199900.
Mechanical
Panel cutout: 45 mm high x 92 mm wide (1/8 DIN)