4300C Programmable Micro-Ohmmeter

For rapid testing of inductive loads, the 4300C’s charge inductor mode provides in excess of 20V compliance. This model reduces settling time by a factor of 5:1 on inductive loads. The result is valid readings in minutes instead of hours when testing 400MW utility transformers. A solid-state “Crowbar” design provides front end protection for up to 500 amps of induced current.

The 4300C Digital Micro-Ohmmeter measures a variety of low-resistance devices ranging in value from 100nΩ to 20kΩ. The flexible measurement format of the 4300C provides six ranges of user selectable test current (from .1mA to 10A) and three voltage sensitivity settings (20mV, 200mV and 2V). The unit’s 4½ digit resistance readings are displayed on a high contrast LCD display and are optionally available via optional BCD, RS-232 or GPIB interface.

  • Test Current to 10 Amps
  • High Compliance Voltage
  • Temperature Compensation Mode (TCM)
  • On/Off Control of Test Current
  • 4-Wire Kelvin
  • Measurement Ranges from 2mΩ to 30kΩ
  • 3 Selectable Pre-Amp Ranges
  • 6 Selectable Test Current Ranges
  • VFD Display w/Adjustable Intensity
  • Hi-LO Resistance Limit Comparator
  • Printout/Log Function
  • Run/Hold w/Peak Detector
  • GPIB-USB-BCD

Primary Interface

+ $495
+ $495
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4300C Configure Options

17025 Certification

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Performance That Conquers Any Resistance

4300C Programmable Digital Micro-Ohmmeter

Features of the 4300C include four terminal compensation, a very low 2mΩ range, selectable test current levels (up to 10 amps), a fast-settling charge inductor mode, safety disconnect status indicators, automatic temperature compensation, a basic accuracy of ±0.03% and a push button or GPIB controlled current on/off selector.

Extraordinary Features

  • User-selectable test-current up to 10A
  • Boosted compliance voltage mode for rapid charging of motors and transformers
  • “Safe to Disconnect” status indicators
  • Test-current “On/Off” switch
  • Selectable voltage sensitivity – 1μV, 10μV, 100μV
  • 18 voltage sense/current combination provide optimal measurement conditions
  • Selectable display refresh (100ms-to-500ms) with variable intensity
  • RS-232 serial interface
  • Programmable-automatic temperature compensation
  • Built-in limit comparator with visual-acoustic indications and rear panel relay terminals
  • Run/Hold w/Peak Detector
  • Print/Log Function

Transformers, Motors, Cables, and More

The 4300C is the perfect instrument for tackling ultra-low resistance testing requirements associated with motors, transformers, fuses, connectors, breakers, bonding/weld resistance, and many other applications. For rapid testing of inductive loads the 4300C’s charge inductor mode provides in excess of 20V compliance. This model reduces the settling time by a factor of 5:1 on inductive loads. The result is valid readings in minutes instead of hours when testing 400MW utility transformers. A solid-state “Crowbar” design provides front-end protection for up to 500 amps of induced current.

Automatic Temperature Compensation

Copper and aluminum will exhibit approximately a 0.4% change in resistance for a 1°C change in ambient temperature. When in Automatic Temperature Compensation mode (TCM), the Valhalla 4300C temperature sensor automatically senses the ambient temperature and references the resistance value of the test item equivalent to being in a 20° C controlled environment. A 10° C change in ambient (i.e. open air, shop floor) provides a 4% change in the resistance of a copper item. Without this “TCM” feature, a micro-ohmmeter which may be 0.02% accurate may be making a 5-10% resistance measurement error when measuring copper or aluminum (i.e., transformer wire) material.

Virtually all competitive micro-ohmmeters lack copper or aluminum (TCM) ambient temperature coefficient of resistivity compensation. Ambient temperature can have drastic effect on the resistivity of a conductor. Without temperature compensation, materials can easily be erroneously classified during the resistance testing process. Correcting the resistance measurement on copper conductors, while ambient temperature varies makes “TCM” a very useful feature.

Large Inductor Resistance Measurement

The 4300C’s 10A current source is ideal for low resistance inductors such as utility transformers. Combining the current output with boosted compliance voltage (>20 VDC) enables rapid stable resistance readings in seconds, not hours. Having unique features like Automatic Temperature Compensation, High Level Current Sourcing (10A) with High Compliance Drive circuitry and 18 combinations of Voltage / Current Range Selectivity, the 4300C Digital Micro-ohmmeter is second to none.

Charging Inductor Mode Indicator

The Valhalla 4300C charging inductor mode LED, indicates when the unit’s current source compliance voltage is exceeded. The 4300C “Boost Mode” then increases the compliance voltage to exceed 20V output to reduce the settling time (charges the inductance) when inductive loads (i.e. large transformers) are being measured.

#
Range
Test Voltage
Full Scale
Resolution
Test Current
Accuracy
(± % reading ± Ω)
Temperature Coefficient
TCM Mode Accuracy
(± % reading ± % ΔT)
12mΩ20mV2.0000mΩ100nΩ10A± .06 ± .0006m±50ppm/°C± .11 ± .0006m
220mΩ20mV20.000mΩ1µΩ1A± .04 ± .006m±50ppm/°C± .09 ± .006m
3200mΩ20mV200.00mΩ10µΩ0.1A± .04 ± .06m±50ppm/°C± .09 ± .06m
420mV2.0000Ω100µΩ10mA± .04 ± .0006±50ppm/°C± .09 ± .0006
520Ω20mV20.000Ω1mΩ1mA± .04 ± .006±50ppm/°C± .09 ± .006
6200Ω20mV200.00Ω10mΩ0.1mA± .04 ± .06±50ppm/°C± .09 ± .06
720mΩ200mV20.000mΩ1µΩ10A± .06 ± .003m±50ppm/°C± .11 ± .003m
8200mΩ200mV200.00mΩ10µΩ1A± .04 ± .03m±50ppm/°C± .09 ± .03m
9200mV2.0000Ω100µΩ0.1A± .04 ± .0003±50ppm/°C± .09 ± .0003
1020Ω200mV20.000Ω1mΩ10mA± .04 ± .003±50ppm/°C± .09 ± .003
11200Ω200mV200.00Ω10mΩ1mA± .04 ± .03±50ppm/°C± .09 ± .03
122kΩ200mV2.0000kΩ100mΩ0.1mA± .04 ± .0003k±50ppm/°C ± .09 ± .0003k
13200mΩ2V200.00mΩ10µΩ10A± .06 ± .03m±50ppm/°C± .11 ± .03m
142V2.0000Ω100µΩ1A± .04 ± .0003±50ppm/°C± .09 ± .0003
1520Ω2V20.000Ω1mΩ0.1A± .04 ± .003±50ppm/°C± .09 ± .003
16200Ω2V200.00Ω10mΩ10mA± .04 ± .03±50ppm/°C± .09 ± .03
172kΩ2V2.0000kΩ100mΩ1mA± .04 ± .0003k±50ppm/°C ± .09 ± .0003k
1820kΩ2V20.000kΩ0.1mA± .04 ± .003k±50ppm/°C± .09 ± .003k

Other Features

The Model 4300C can also be programmed for Hi-Lo limit comparison. Three front panel LEDs allow a visual of the result and a rear panel relay closure screw terminal block can be used to implement an automated batch sorting system for components or products, operate counters, sound alarms or shut off a process. A Run/Hold function is also a standard feature of the 4300C. The user can program this function as a peak hi or peak low detector. Measurements may be printed or logged and viewed in a spread sheet by using the Print/Log feature also standard with the Model 4300C.

General Specifications
Display Type: 5 digit VFD
Overload Indication:Flashes OVERLOAD
Conversion Rate:45 readings per second
Terminal Configuration:4-Wire Kelvin
Max Kick-Back Protection:500A Peak Induced Current
Compl. Voltage (Normal Mode):7.5 VDC Nominal @ 10A resistive
Compl. Voltage (Charging Inductor Mode):20 VDC when indicator is on
Test Current Polarity:Positive (flows High to Low)
Open Circuit Voltage (Test Current Off):< 20mV
Power
Power Requirements:115VAC or 230VAC ±10%
Temperature
Operating Temp. Range:0°C to 50°C
Storage Temp. Range:-40°C to 85°C
Humidity:80% RH max @ 40°C (non-condensing)
Physical Specifications
Width|Depth|Height: 17” / 43cm | 11.5” / 29.5cm | 4” /10cm
Weight:20lbs / 9 kg net;
#RangeTest VoltageFull ScaleResolutionTest Current1Accuracy(± % reading ± Ω)Temperature Coefficient3TCM Mode Accuracy(± % reading ± % ΔT)
  1. Current source is ±1% absolute accuracy
  2. Accuracy specs are valid following a 30 minute warm-up at an ambient temperature between 22°C and 28°C, and include the effects of line voltage variations within the allowed range.
  3. Temp. Coefficient specified for temp. ranges from 5°C to 21°C and 29°C to 50°C.
  4. Accuracy specifications valid following a 30 minute warm-up at an ambient temperature between 21°C and 29°C.
12mΩ20mV2.0000mΩ100nΩ10A± .06 ± .0006m±50ppm/°C± .11 ± .0006m
220mΩ20mV20.000mΩ1µΩ1A± .04 ± .006m±50ppm/°C± .09 ± .006m
3200mΩ20mV200.00mΩ10µΩ0.1A± .04 ± .06m±50ppm/°C± .09 ± .06m
420mV2.0000Ω100µΩ10mA± .04 ± .0006±50ppm/°C± .09 ± .0006
520Ω20mV20.000Ω1mΩ1mA± .04 ± .006±50ppm/°C± .09 ± .006
6200Ω20mV200.00Ω10mΩ0.1mA± .04 ± .06±50ppm/°C± .09 ± .06
720mΩ200mV20.000mΩ1µΩ10A± .06 ± .003m±50ppm/°C± .11 ± .003m
8200mΩ200mV200.00mΩ10µΩ1A± .04 ± .03m±50ppm/°C± .09 ± .03m
9200mV2.0000Ω100µΩ0.1A± .04 ± .0003±50ppm/°C± .09 ± .0003
1020Ω200mV20.000Ω1mΩ10mA± .04 ± .003±50ppm/°C± .09 ± .003
11200Ω200mV200.00Ω10mΩ1mA± .04 ± .03±50ppm/°C± .09 ± .03
122kΩ200mV2.0000kΩ100mΩ0.1mA± .04 ± .0003k±50ppm/°C ± .09 ± .0003k
13200mΩ2V200.00mΩ10µΩ10A± .06 ± .03m±50ppm/°C± .11 ± .03m
142V2.0000Ω100µΩ1A± .04 ± .0003±50ppm/°C± .09 ± .0003
1520Ω2V20.000Ω1mΩ0.1A± .04 ± .003±50ppm/°C± .09 ± .003
16200Ω2V200.00Ω10mΩ10mA± .04 ± .03±50ppm/°C± .09 ± .03
172kΩ2V2.0000kΩ100mΩ1mA± .04 ± .0003k±50ppm/°C ± .09 ± .0003k
1820kΩ2V20.000kΩ0.1mA± .04 ± .003k±50ppm/°C± .09 ± .003k

 

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