or ▁revers ing ▁time ) ▁during ▁operation ▁of ▁a ▁T EM . ▁R ather ▁than ▁using ▁an ▁a pert ure ▁to ▁control ▁detected ▁electrons , ▁as ▁in ▁T EM , ▁a ▁S TE M ▁uses ▁various ▁detect ors ▁with ▁collection ▁angles ▁that ▁may ▁be ▁adjust ed ▁depending ▁on ▁which ▁electrons ▁the ▁user ▁wants ▁to ▁capture . ▁ ▁Low - vol t age ▁electron ▁mic ros cope ▁A ▁low - vol t age ▁electron ▁mic ros cope ▁( L VE M ) ▁is ▁operated ▁at ▁relatively ▁low ▁electron ▁acceler ating ▁voltage ▁between ▁ 5 – 2 5 ▁k V . ▁Some ▁of ▁these ▁can ▁be ▁a ▁ ▁combination ▁of ▁SE M , ▁T EM ▁and ▁S TE M ▁in ▁a ▁single ▁compact ▁instrument . ▁Low ▁voltage ▁increases ▁image ▁contrast ▁which ▁is ▁especially ▁important ▁for ▁bi ological ▁spec im ens . ▁This ▁increase ▁in ▁contrast ▁significantly ▁reduces , ▁or ▁even ▁elimin ates ▁the ▁need ▁to ▁st ain . ▁Resol utions ▁of ▁a ▁few ▁n m ▁are ▁possible ▁in ▁T EM , ▁SE M ▁and ▁S TE M ▁modes . ▁The ▁low ▁energy ▁of ▁the ▁electron ▁beam ▁means ▁that ▁permanent ▁magnet s ▁can ▁be ▁used ▁as ▁l enses ▁and ▁thus ▁a ▁mini ature ▁column ▁that ▁does ▁not ▁require ▁cool ing ▁can ▁be ▁used . ▁ ▁Cry o - TE M ▁Main ▁article : ▁Trans mission ▁electron ▁cry om icro sc opy ▁ ▁Cry ogen ic ▁transmission ▁electron ▁micro sc opy ▁( C ry o - TE M ) ▁uses ▁a ▁T EM ▁with ▁a ▁spec imen