Laurel Electronics Laureate Ohmmeter for Resistance in Ohms or Milliohms - Manual

LAUREL ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
LAUREL
ELECTRONICS, INC.
Laureate™ Ohmmeter for Resistance
in Ohms or Milliohms
Features
• Five precalibrated resistance ranges from 20.000 ohm to 200.00 kohm
• 2.0000 Mohm resistance range with factory modification
• 1 mohm resolution on 20 ohm scale
• 2, 3 or 4-wire connection with lead resistance compensation
• Highly accurate and repeatable
• Up to 60 conversions per second
• Peak or valley display
• Universal AC power, 85-264 Vac
• 1/8 DIN case sealed to NEMA-4X from front panel
• Optional serial I/O: Ethernet, USB, RS232, RS485, Ethernet-to-RS485 converter
• Optional relay output: dual or quad relays, contact or solid state
• Optional isolated analog output: 4-20 mA, 0-20 mA, 0-10V, -10 to +10V
• Optional low voltage power: 10-48 Vdc or 12-32 Vac
Description
The Laureate Ohmmeter is ideal for high-speed, high-accuracy
resistance measurements in a production environment, such as
contact resistance measurements. It is factory calibrated for five
jumper selectable resistance ranges from 20 ohm to 200 kohm.
Accuracy is an exceptional ±0.01% of full scale ± 2 counts.
Resolution is one part in 20,000. In the 20-ohm range, resolution
is 1 milliohm, making the meter suitable for contact resistance
and conductance measurements. An additional 2 Mohm range is
available with a factory modification.
Meter connections can be via 2, 3 or 4 wires. With 4-wire
hookup, 2 wires are used for excitation and two separate wires
are used to sense the voltage across the resistance to be
measured, thereby eliminating any lead resistance effects. With
3-wire hookup, the meter senses the combined voltage drop
across the resistance to be measured plus two excitation leads.
It also senses the voltage drop across one excitation lead, and
then subtracts twice this voltage from the combined total. This
technique effectively subtracts lead resistance if the excitation
leads are the same.
All resistance ranges are digitally calibrated at the factory, with
calibration factors stored in EEPROM on the signal conditioner
board. This allows ranges and signal conditioner boards to be
changed in the field without recalibrating the meter. If desired,
the meter can easily be calibrated using external standards plus
scale and offset in software.
Multiple relay operating modes are selectable in software. One
of these is band deviation setpoint operation, where a deviation
limit (such as 50 counts) is set up around both sides of the set-
point. The relay closes (or opens) when the reading falls within
the deviation band, and opens (or closes) when the reading falls
outside of this band. This mode sets up a passband around the
setpoint and is often used for component testing.
Designed for system use. Optional plug-in boards include
Ethernet and other serial communication boards, dual or quad
relay boards, and an isolated analog output board. Laureates
may be powered from 85-264 Vac or optionally from 12-32 Vac
or 10-48 Vdc. The display is available with red or green LEDs.
The 1/8 DIN case meets NEMA 4X (IP65) specifications from the
front when panel mounted. Any setup functions and front panel
keys can be locked out for simplified usage and security. All
power and signal connections are via UL / VDE / CSA rated
screw clamp plugs.
Specifications
Range Resolution Accuracy Excitation Current
0-20.000 ohm *
0-200.00 ohm *
0-2000.0 ohm *
0-20000 ohm*
0-200.00 kohm *
0-2.0000 Mohm **
1 mohm
10 mohm
100 mohm
1 ohm
10 ohm
100 ohm
±0.01% of range
± 2 counts
5 mA
500 µA
50 µA
5 µA
500 nA
500 nA
* Jumper-selectable, precalibrated range.
** Factory-set fixed range