Capillary with narrow bore – produces a greater change in the length of the mercury column. A glass bulb with thinner wall – Heat can be transferred to the bulb easily. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.25 842] /Contents 12 0 R/Group<>/Tabs/S/StructParents 2>>
It is calculated in meter/degree Celsius. Sensitivity is defined as the ratio of the change in output value to change in input signal. endstream endobj Acids are all: sour, corrosive and soluble in water All alkalis are the chemical opposite of acids, have a so...There are two muscles in the iris: the circular muscle and the radial muscle, the diagram below shows both of them Courtesy of http://ge...Capillary tube - A glass tube with thick walls and a narrow interior hollow tube (bore). If one junction is at a higher temperature than the other one, an electric current flows, producing a reading on a digital voltmeter, the voltage of the current is directly related to the temperature.They are used in industry to measure a vast range of temperatures from -250℃, they are also very good at measuring the temperatures on small objects or for rapidly changing temperatures.Resistance thermometers are used to measure temperatures accurately from -200They work by using the fact that electrical resistance builds up in a platinum wire when the temperature increases. 1 0 obj stream When designing bridges, railway...What are acids and alkalis? GCSE Keywords: Scale, Linear, Precision, Sensitivity ... Thermometers and temperature 16.
� ���ݚ�#yS 11 0 obj By flicking your wrist, the mercury returns to the bulb again.Mercury thermometers (for clinical use) are now being replaced by digital thermometers, because mercury is toxic.Thermocouples are used to measure temperatures that change quickly or are very high.Thermocouple thermometers have wires made of two different materials, e.g iron and copper that are joined together.
Image source and credit: http://www.advancedaquarist.comTo the left is a labelled diagram of a thermometer, you don't need to know all of the different parts of a thermometer, but I included it to help you understand.When the glass bulb is is heated, the liquid in the bulb starts to expand up the capillary tube. The sensitivity of a thermometer can be increased by Using a thermometer with a smaller bulb – A smaller bulb contains less mercury and hence absorbs heat in shorter time. Thermistors Thermistors work over a small range, ie.
4 0 obj I design temperature sensors as part of my job. stream Constant-Volume Gas Thermometers Constant-Volume Gas thermometers use the change in pressure of a gas to measure temperature. We'll assume you're ok with this, but you can opt-out if you wish.Accept Read More. <>
}�y��|�}�E��vpy߀)%���}dJO>�Ec�R�����Ф���u�6����D���z��G�e�%��w��G�Z�/Iuإ��Q��e8@�S��Q��I�zR]��A��I��^!h���}4�� mR��xO��I��^�}�D¤�z��o�4���C#lp�8N��>v�߆H��ꥱ"v$M�����Uɱ4����E�6���IX7����.&��u�L.#&��+�ˈIQ�2�|�����x3� #r4�ށu�8�ޡ�)� So I know there's not much on here at the moment, but I'm getting there. 2 0 obj �$��B <> They are best used for steady temperatures and are bulky.Constant-Volume Gas thermometers use the change in pressure of a gas to measure temperature. endobj -5 ℃ to 70 ℃. Once the thermometer is removed from the mouth, the mercury in the bulb cools and contracts, breaking off from the mercury thread at the constriction, but the mercury that's beyond the constriction stays in the tube, showing the body temperature is at. These are different from normal mercury-in-glass thermometers as their scale only extends for a few degrees either side of 37The capillary tube in these thermometers is very narrow, allowing for a very accurate reading to be taken, a.k.a The capillary tube has a constriction (check diagram above if you don't know what this is) just above bulb.The thermometer is placed under the tongue and kept there for 1 minute, the mercury expands it heats up and forces past the constriction. endobj
Sensitivity, range and linearity of measuring instruments-Sensitivity, range and linearity. endobj x��][��6~`����VěH-��� Z4��f�}X�c{y��Y����e��l�����ls}�����Տ(C4����B�]����9�,��/�n�d�wx���;��:�ٻ�O>L���tVM��36y~�b1Ye��|R�7�)��3�[-28Tm����0�!��}��;�;x�m4�ù"���b���'�������\_�1$Ceg0H!r!��(r$�"����e�ux�j`�.j�����3���Wl�}s}����M�u� �_�_Z��]�b�Ƙ�Ù�Qf0�i���S�&�鬔�. %PDF-1.7 <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.25 842] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 8 0 obj ○To increase the sensitivity of a thermometer, use a bigger bulb or a narrower bore. <> endobj The range of a liquid-in-glass thermometer is limited by the length of the thermometer and can be increased by: increasing the diameter of the capillary – this means that the liquid will not expand as far along the tube per degree rise in temperature.