Xytronic LF-1000 Soldering Station - Calibration - Page 1
Forum section: electronics / general

author: dexters_lab
author_rank: Unknown
timestamp: February 03, 2014, 11:22:35 pm
content: I have my trusty Xytronic soldering station here, i have a couple of questions about calibration of the temperature display.For a long time i have noticed that i have to turn the temperature up way more than i would expect so figured the cal was out a bit.After doing some measurements it seems right at the tip end it's about 50C less than the indicated temperature, where the tip exits from the housing that holds the tip in place it's maybe 10C to lowOn this station there is a front accessible cal adjustment but that only seems to give me about 25C of adjustment and was already on it's max.Inside there is a display board containing a intersil 3.5 digit ADC and a power board. Including the front trim there are 9 trim pots with one of them gunked over so i dont fancy fiddling!So, two questions...A) does anyone have any knowledge of calibrating this unit or know of a schematic?B) acceptable procedure for measuring iron tip temperature?

author: valentinc
author_rank: Regular Contributor
timestamp: February 04, 2014, 01:06:23 am
content: According to the datasheet of the ICL7107, the voltage reference of the ADC is set at pin 36 (with respect to ground)... In the typical application from the datasheet there is a pot there (1K)... Try to find that pot on the board and play with it...About measuring the temperature of the tip, I think a K type thermocouple together with a multimeter is more than enough for this application... You don't need it to be spot on... If it's a couples of degrees out, it doesn't really matter...

author: dexters_lab
author_rank: Unknown
timestamp: February 04, 2014, 10:26:48 am
content: thanks, i have a k-type probe, i think i am really asking where i should be measuringon the attached pic, if i measure where the tip enters the body of the heater (red circle) it's within about 10C of the indicated temp. Right at the tip (green circle) it's about 50C less than indicated on the station.If this is 'normal' and all irons measure the temperature like this i will just leave it and not touch anything.i guess different tips would have different gradients between the heater and the actual wet part of the tip

author: valentinc
author_rank: Regular Contributor
timestamp: February 04, 2014, 12:36:21 pm
content: dexters_lab: I just checked one of my soldering stations (http://pictures.content4us.com/products_high_res/HQ-SOLDER30.JPG) and it was reading 378 degrees C on its display, when I measured at the tip (green circle) I was reading about 250 degress C and at the body of the heater I was reading about 300 degress C...I think the problem is that what the station displays, is the reading from the temperature sensor INSIDE the heater element, which is clear that is way hot than the tip itself... Because there are losses in the metal...My opinion is to leave it exactly as it is...

author: dexters_lab
author_rank: Unknown
timestamp: February 04, 2014, 01:08:14 pm
content: thanks guys!nice to have this confirmed

author: dexters_lab
author_rank: Unknown
timestamp: February 05, 2014, 06:46:09 pm
content: Thanks wilfredYes your station does look like the xytronic!