Measurements International’s series of Low Thermal Scanners are ideal for automating precision measurements to sub-ppm accuracy. The Model 4210, 4216 or 4220 series of low thermal precision scanners are ideal for use in automated resistance and thermometry applications where several artifacts need to be calibrated efficiently and accurately. This series of Matrix Scanners improves the efficiency by eliminating the need to continually change leads when measuring groups of resistors. The input channels can be manually selected from the front panel or via the standard IEEE488 Interface when used in an automated system. LED’s on the front panel enable the operator to quickly verify which channels have been selected. Front panel LEDS designated A and B indicate the selected channels. Additionally, the A and B boards are separated to improve the insulation resistance. Protection from selecting the same relay on both sides is also available on the rear panel IEEE address switch. The relay boards are thermally isolated to maintain equilibrium in the switching areas. Furthermore, the A and B boards are separated to improve the insulation resistance. Ultra sensitive, high efficiency, polarized sealed relay technology is used to eliminate self-heating in the relay. Sealed relays have the advantage that they avoid contamination buildup commonly found in competitive scanners where contamination builds up between the relay contacts and the contacts on the printed circuit boards. A choice of six scanners is available. 10 channel, 16 channel, and 20 channel with either Tellurium copper binding posts or 2-meter four-conductor Teflon cables. In the A series of scanners, the copper terminals are mechanically connected to the copper pads on the relay boards to reduce the thermals normally generated by soldered connections, thus reducing switching errors. The B Series features four-conductor Teflon Cable inputs with 2 four-conductor Teflon Cable outputs attached directly to the relay boards reducing the number of contacts. Each B series scanner comes with a 2-meter lead. As an option, the leads can be extended to 3 or 4-meters. The Model 4210A has 10 four terminal input channels consisting of 40 tellurium copper binding posts and 2 four channel outputs consisting of eight tellurium copper binding posts. The 4216A has 16 four terminal tellurium copper binding posts and 2 outputs consisting of 8 tellurium copper binding posts. The Model 4216B has 16 four-conductor Teflon cable inputs with 2 four-conductor Teflon cable outputs. The 4220A has 20 four terminal tellurium copper binding posts and 2 outputs consisting of 8 tellurium copper binding posts. The Model 4220B has 20 four-conductor Teflon cable inputs with 2 four-conductor Teflon cable outputs. The 4220A is also available in a 30 amp model to handle currents up to 30A (model 4220A/30).
