High Resistance / Low Conductance (HRLC) Meter
The HRLC meter measures resistance in six ranges from 1 K ohm to 1.9999 T ohms (1.9999x1012 ohms), and conductance in two ranges. covering from 0.001 pico siemens (pS) to 19.999 nano siemens (nS), all at low voltage of < 4 volts. Basic accuracy is +/- 2% of reading +/- 1 count. The highest measurable resistance is effectively 1000 T ohms (1015), which will be measured as a conductance of 0.001 pS. The meter includes conductance ranges because samples with simultaneously high resistance and high capacitance settle faster to their final value on conductance than on resistance. Note that resistance in units of T ohms is the inverse of conductance in pS, so that the resistance can be calculated from the conductance. For example, 100 pS is 0.01 T ohm (10 G ohm), and the highest readable conductance of 199.99 nS is essentially 5 M ohms.
High Resistance/Low Conductance Meter: $520 (US dollars): BUY IT NOW
Price includes shipping in the US. For shipping to Canada by Express Post add $20 (US dollars). Outside the US and Canada add $40 (US dollars).
The resistance ranges are 19.999 M ohms (one minimum digit represents one K ohm), 199.99 M, 1999.9 M, 19.999 G, 199.99 G, and 1999.9 G ohms. The single conductance ranges are 19.999 pS and 19.999 nS. There are two offset controls; one control sets the "zero" for resistance, which is determined while the terminals are shorted together. When set correctly, all nine ranges will read zero, and this control will generally never need to be altered. (It is set correctly as shipped.) The other offset control is a knob on the right side. It should be set for zero while on the 19.999 pS range with nothing connected to the terminals. This offset is slightly temperature-sensitive, and should be re-zeroed if the temperature changes by more than 5ºC. With each of the six resistance ranges, there is a constant current that flows through the unknown resistance. Current decreases by factors of ten, from 100 nA on the 19.999 M range, to 1 pA on the 1999.9 G range. On both conductance ranges, 3.5 volts are applied across the unknown resistance.
The resistive sample (unknown resistance) is connected at two points; the "Non-Sensitive Terminal" is the source of current (or of 3.5 volts in the conductance ranges), and the "Sensitive Terminal" is connected to a high-impedance amplifier, which uses feedback to hold the sensitive terminal at ground potential. There are several ways to connect the sample. In the photo, a piece of sandpaper is held by the short clips. 80 cm cables are also included. When measuring high resistance, the sensitive terminal should be shielded from any people or objects moving nearby because moving charges will cause interference. A snap-in conductive box (Faraday cage) is included to eliminate interference when measuring small samples. For large samples, if the meter is placed in an open-top metal box or a simple aluminum foil enclosure (with the top open to see the meter), this interference will be significantly reduced. When using a metal box, the interference is reduced further if the meter ground ("Shield") is connected to the box.
The meter is battery-powered with a standard 9 V replaceable battery (included), which operates about 40 hours before the low battery indicator comes (on indicating about one more hour of battery life). It is shipped ready-to-use and the warranty period is one year.
Instructions and suggestions for measuring high resistance.
SPECIFICATIONS
Measures resistance in 6 ranges from 19.999 M ohms to 1999.9 G ohms. Accuracy is +/-2% of the reading +/- 1 count. The 6 measurement currents are 100 nano amps down to 1 p amp in factors of 10.
Measures conductance in 2 ranges: 19.999 nano siemens and 19.999 pico siemens. Accuracy is +/-2% of reading +/- 1 count. During conductance measurements, 3.5 Volts is applied across the component.
A "RESPONSE SPEED" control allows selection of either FAST meter update (1/3 second time constant), or SLOW (2 second).
Noise: for resistance greater than 10 G ohms, RMS noise per 1/3 sec sample (FAST) is 0.0007 pico siemens. For less than 10 G ohms, RMS noise per 1/3 sec sample is (10G ohms/R)1/2 x 0.0007 pico siemens. The noise per 2 sec sample (SLOW) is approximately half as much. The effect of this thermal noise on the displayed resistance can be calculated by first converting the expected resistance value to conductance (by inverting). Then add or subtract the conductance noise and convert back to resistance, These resulting "added" and "subtracted" numbers are the 70% confidence limits of the displayed resistances, ignoring outside interference.
Battery is a standard rectangular 9 Volt type, with "LOW BATTERY" appearing on the display when approximately one hour of battery life remains. Battery life is about 40 hours using an alkaline, and 25 hours using a regular battery. A battery is included.
High Resistance/Low Conductance Meter: $520 (US dollars). BUY IT NOW
Price includes shipping in the US. For shipping to Canada by Express Post add $20 (US dollars). Outside the US and Canada add $40 (US dollars).
Warranty for this meter is one year. Made by AlphaLab, Inc. (USA).
For information or to place an order :
AlphaLab, Inc. (USA). Tel. +1-801-487-9492
Toll free (from USA and Canada) 1-800-658-7030
Fax us at +1-801-487-3877
E-mail us at mail@trifield.com