Leica DM IRB manual Colour coding of the objectives, White Water, Locking of objectives

Colour coding of the objectives

The magnification of each objective is indicated as per DIN/ISO standard by a colour ring:

100x	63x	40x	25x	16x	10x	6.3x	4x	2.5x	1.6x
125x		50x	32x	20x			5x
150x
160x
white	dark	light	dark	light	yellow	orange	red	brown	grey
	blue	blue	green	green

Immersion objectives also have a second colour ring underneath:

Black Oil or IMM (= universal for oil, water, glycerine)

White Water

Orange Glycerine

Fig. 91 Immersion objectives

1, 2 Oil immersion objectives (OIL), 1 in working position,

2locked in shortened position, 3 Water immersion objective (W), 4 Universal immersion objective (IMM) for water, glycerine, oil, 5 Colour coding for immersion, 6 Knurled ring for screwing down

The different colour of the objective engraving indicates the use of the objective:

Black or	Brightfield objectives,
dark blue	low-strain
Green	Phase contrast objectives,
	low-strain

Locking of objectives

The front part of immersion objectives (OIL, W, IMM) can be pushed up (91.1 and 91.2) by about 2 mm and locked in a shortened position by a slight rotary movement. This stops any remaining drops of immersion liquid from wetting specimens or other objectives when the nosepiece is turned.

5

6

1 2 3 4

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