simpson 444 Micro-Ohmmeter

High accuracy and a high resolution 4-1/2 digitLCD display make the 444 perfect for testing conductive coatings,high power fuses, and antenna grounding systems. With a testvoltage of only 100uV, the 444 will not "punch through"contamination or corrosion. The 444 comes with a test lead with aBNC connector on one end and a Kelvin clip on the other, manual,line cord and Ni-Cad battery for field use.

• AC pulse or DC polarity switching measurementmethods
• Measures from 1 micro-ohm to 20 ohms
• AC lined-powered or battery-powered for lab orfield use
• User-adjustable, low-resistance alarm

• Measures from 1 Micro-Ohm to 20 Ohms
  Simpson’s high precision Model 444 Micro-Ohmmeter measures resistance from 1 micro-ohm to 20 ohms. It measures using an extremely small test voltage (100 microvolt maximum) and a four wire measurement technique. The resistance reading is indicated on a 4- 1/2 digit LCD display using one of two measuring modes: An automatic AC measurement mode or a manual DC measurement mode.By limiting the test voltage of the Model 444 to only 100 micro volts the instrument will not "punch through" contamination or corrosion. An audible tone can be used to indicate resistance values below any selected reading. The Model 444 is powered by either a 120 or 240 AC source or, from self-contained rechargeable Ni-Cad batteries for field use.
  20,000 Count 4 1/2-Digit LCD			Specifications (Continued)
  2 Measurement Methods: AC Pulse and DC Polarity Switching			Relative Humidity: 90% maximum up to 35°C, 70% maximum up to +50°C (non-condensing)
  8"Punch-Through" Prevention by 100 _V Max.Test Voltage			Temperature Coefficient: 0.1 times the applicable accuracy specification per °C (0° to 18°C and 28° to 50°C)
  User-Adjustable, Low-Resistance Alarm			BatteryVoltageEffect: Plus orMinus (0.15% of input); Fully charged to "B"
  AC Test Mode Cancels Offset Voltages and Thermocouple Effects			annunciator displayed
  Includes Ni-Cad Battery for Field Use and Test Leads			BatteryLife:8 hourstypical
  Specifications			Rated Circuit-To-Ground Voltage: 30V (RMS)
  Range	Resolution	Maximum Test Current	Dimensions: 2.7" x 8.4" x 9.0" (68 x 213 x 228 mm) nominal
  20mΩ	1μΩ	5mA
  200mΩ	10μΩ	500μA
  2Ω	100μΩ	50μA
  20Ω	1mΩ	5μA	Weight: Approximately 3 Ibs.