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Article No.: A50070
Articlename: Autosampler 3950

Autosampler 3950

standard version, 1000 bar

The Autosampler 3950 can inject from up to 768 positions when equipped with microtiter plates (either high or low formats) or from up to 96 standard 2 ml sample vials. Sample carryover is significantly minimized thanks to a highly-effective interior and exterior needle wash procedure. This autosampler is also fast and flexible: one complete sample injection cycle takes less than one minute, including needle wash. Three different injection modes are supported; “full loop filling” (highest precision and reproducibility), “partial loop filling” (variable volumes, e.g. for dilution series) and “µl pickup” (loss-free injection of extremely small sample volumes), allowing the user to optimize sample usage. The headspace pressure function prevents bubbles from forming in the vial during sample uptake. Precolumn derivatization is supported. For high-pressure injections of up to 1000 bar, the autosampler is equipped with a so-called ILD™ valve (Intermediate Loop Decompression). This valve consists of a rotor-stator combination and includes a central port for depressurizing. For highpressure applications, the sample loop is depressurized prior to receiving the sample. This way, the sample is not diluted with solvent. Because the valve is switched extremely fast, pressure spikes are reduced. Analyses are more precise and wear of the column is reduced.

Key Features

Technical Data

Sample injection

Sample capacity microtiter plates for max. 768 samples or sample plates for max. 96 vials
Vial/plate dimensions max. plate/vial height: 47 mm (incl. septa or capmat)
Injection volume range 0.1–5000 µl programmable
Sample loop 10 µl standard
Dispenser syringe 250 µl
Headspace pressure built-in compressor, only for vials with septum
Switching time inj. valve < 100 ms
Piercing needle precision ± 0.6 mm
Sample tray cooling None
Vial detection missing vial/well plate detection by sensor
Needle wash programmable: wash between injections and wash between vials
Wetted materials stainless steel (SS316), Tefzel®, Vespel®, glass, Teflon® (PTFE).

Analytical performance

Injection modes full loop, partial loopfill and µl pickup mode; PASA™ (pressure-assisted sample aspiration)
Injection volumes full loop: max. 5000 µl /partial loop: max. 2500 µl (50% loop volume)/µl pickup: max. 2455 µl (50% loop volume - 1,5x needle volume) 0.1 µl increment for all injection modes
Injection precision RSD (Relative Standard Deviation): full loop injection: <0.3% partial loop injection at an injection volume>10 µl: <0.5% microliter pickup injection at an injection volume>10 µl: <1.0%
Sample carryover < 0.05 % with programmable needle wash
Injections per vial max. 9 injections
Injection cycle time minimum 7 s from the same vial, 14 s from different vials; < 60 s for ≤ 100 µl sample injection in all injection modes, incl. 300 µl needle wash
Analysis time max. 9 h, 59 min, 59 s


Inputs 2 programmable TTL inputs (next injection, freeze, stop)
Outputs 1 programmable relay output (inject marker, auxiliary, alarm)
Control Ethernet (LAN)

Technical parameters

Ambient conditions temperature range: 4–40 °C; 39.2–104 °F air humidity: below 90 % humidity (non condensing)


Power supply 90–230 V AC ± 10 %; 50–60 Hz; 200 VA
Dimensions 300 x 360 x 510 mm (W x H x D)
Weight 19 kg

Documents and more information

Certified Quality 

KNAUER is known for the quality of its products and has been certified several times. We produce high-tech laboratory instruments for research, routine analysis and production.
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In addition, we have extended documentation about all our products, including CE Declarations of Conformity.
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