The QA350 is currently out of stock. It will be replaced by the QA351, which will hopefully be shipping by the end of June or early July. If you obsess over measuring voltage and have a lot of in-house references (especially higher voltage references >> 10V), we might be able to send you a pre-production QA351 to evaluate. Contact us at the 'sales' alias. The QA351 has two channels: The main channel has two ranges, +/-50V and +/-5V, with 1M and 10M input Z respectively. The aux channel is +/-50V in a single range. The main channel delivers single-digit uV resolution with 400 mS conversion time and the aux channel delivers single digit mV resolution with 100 mS conversion time.
Every lab needs a high-resolution logging DVM. The QA350's fully isolated design allows low-noise DC measurements in a variety of settings, including chemistry, semiconductor development, battery development and high-accuracy sensor verification.
The QA350 relies on a built-in reference to calibrate the ratio between the hi and low ranges. If you have a preferred lab reference, you may use that it to improve the QA350 accuracy beyond the indicated +/- 400 PPM. For example, various vendors on eBay can provide calibrated +/-30 PPM 5 or 10V voltage references that can be used to set the ultimate accuracy of the QA350 to under 50 PPM at room temperature.
The core of the QA350 is a TI ADS1256 24-bit ADC, capable of delivering 23-bits of noise-free resolution. The ADS1256 reference is provided by a very high quality MAX6126A 2.048V reference rated at +/- 200 PPM.
Important note: The QA350 is NOT for use on high-energy circuits or circuits directly connected to the mains. It is rated as CAT I, which is the "weakest" safety category rating. DO NOT USE THE QA350 ON CIRCUITS THAT ARE POTENTIALLY HAZARDOUS OR LETHAL. It is meant for measuring ultra precision transducers, DACs, opamps and any other circuit where you need precision.
Isolated and fully differential (max offset from PC ground is +/- 100V. Tested to >10G ohm at 1000V input ground to chassis ground)