The Zeiss 1555 VP-FESEM is a high-resolution, field-emission variable-pressure (VP) scanning electron microscope (SEM).

The instrument can operate in normal high-vacuum SEM mode or in variable-pressure mode (VPSEM) with a chamber gas (usually air) pressure up to ~130 Pa, and at low temperature (cryoSEM). In SEM mode state-of-the-art performance including sub-nanometre beam resolution (@20kV) and very low voltage (to 100v) imaging conditions can be achieved. In VPSEM, samples can be imaged uncoated with medium resolution. With cryo samples can be imaged frozen, at temperatures as low as -150C. In all modes X-ray microanalysis can be performed using Oxford Instruments X-Max 80 silicon drift EDS system with AZtec and INCA software. It is capable of analysis for elements in the range Be to Pu. Capable of processing X-Ray count rates in excess of 500,000 cps, it can also rapidly generate X-ray element distribution maps and line profiles. AZtec TruMap and TruLine software applies background and overlap corrections to map and line data to provide artefact-free element distribution images. QuantMap software in the INCA package can provide quantitative mapping data.


The instrument is optimised for routine low-voltage (<5 kV) medium-high resolution imaging and is suited to samples from all fields.


  • Variable pressure secondary electron imaging
  • High-resolution secondary electron imaging using an in-lens SE detector in high-vacuum mode
  • Low-voltage backscattered electron imaging in VP and SEM
  • Qualitative X-ray microanalysis and element X-ray mapping (Z>3)
  • Quantitative EDS X-ray microanalysis
  • Qualitative, artefact-free X-ray element mapping
  • Cathodoluminescence imaging
  • Charge contrast imaging in VP mode
  • Low temperature (cryo) imaging and microanalysis

Instrument specifications

  • 0.1-30kV, inlens, BSD, SE, CL, EDS and variable pressure (up to 133 Pa, dry only) capabilities
  • Low-voltage in-lens SEI of bacteria in a tooth filling
  • High count rate silicon drift EDS system
  • 0.1-30kV, inlens, BSD, SE, CL, EDS, variable pressure (up to 133 Pa, dry only)
  • Cryo capabilities