Sprengel pyknometer

The density of a liquid is most easily determined by means of vessels known as pyknometers, the volume of which need not exceed 1 c.c. Perkin s modification (Fig. 42) of the Sprengel pyknometer is well adapted for small quantities of liquid and also for volatile liquids. The apparatus which usually has a volume of 2—10 c.cs. consists of a U-tube, the limbs of which are drawn out to capillaries, and bent as shown. On limb A a small bulb is blown, and below this a ring is etched round the capillary. 

A twin pyknometer method with specific gravity bottles giving an accuracy of 1 in 10<5, is described. 12 The use of a bottle with two graduated capillary necks (based on the Sprengel pyknometer, bicapillary pyknometer ), gives an accuracy of 5 in 10. In very accurate work a correction for the weight of the vapour of a volatile liquid in the unfilled neck of the bottle, pyknometer, or dilatometer (see below), should be applied, i" ... 

The density of liquids is most easily determined by means of vessels of accurately defined volume, called pyknometers. These are made of very varying shapes, but the simplest and most generally useful form is the Ostwald modification of the Sprengel pyknometer (Fig. 6). 

A very delicate and useful piece of apparatus, which is leadily made with the blow-pipe, is Perkins modification of Sprengel s pyknometer. It is especially adapted for small quantities of liquid and for the moie volatile ones. The apparatus (Fig. 46) consists of a U l ube to hold from 2 to 10 c.c., drawm out at each end into a fine capillary. The one capillaiy limb, a, is bent outwards and is furnished with a small bulb the other, b, is bent at a right angle with the first. On the limb a, between the bulb and the top of the U-tnbe a mark is etched. The... 

---

See also in sourсe #XX -- [ ]

---