Contactless Thermometer

Are you running an infrared temperature?

Published in issue 2/2011 on page 48

This thermometer measures at the same time both the ambient temperature and the temperature of any object placed within its ‘field of view’. And even though the ambient temperature range ‘only’ goes from −40 to +125 °C, the object temperature can be from −70 to +380 °C, and all with an accuracy of 0.5 °C and a measurement resolution of 0.02 °C.




Resistors (0.25W 5%)
R1,R4,R6 = 10kOhm
R2, R5 = 100Ohm
R3 = 1.5kOhm
P1 = 10 kOhm trimpot, horizontal
C1,C3 = 100µF 16V, radial, lead pitch 2.5mm
C2 = 470nF 63V, MKT, lead pitch 5 or 7.5mm
C4 = 10µF 25V, radial, lead pitch 2.5mm
C6 = 100nF ceramic, lead pitch 5 or 7.5mm
C7 = 10nF ceramic, lead pitch 5 or 7.5mm
L1 = 10µH, Panasonic type ELC08D100E (RS Components)
IC1 = LT1300
D1 = 1N5817 (must-have Schottky)
D2 = 3.3V 0.4W zener diode
X1 = 20MHz quartz crystal, HC18/U case
S2 = swich, changeover, or wire link
Pinheder pins, lead pitch 0.1’’ (2.54mm)
Pinheder sockets, lead pitch 0.1’’ (2.54mm)
PCB, Elektor # 100707-1