Hello, I have a AS conductivity sensor and a ph AS sensor. I downloaded their sample sketches. Each of them work well on its own. However, when I try to use them ay the same time on th Arduino, (sensors has their own pins.) I combine the two sketches into one, they do not play well together. The ph part runs fine but the conductive droppes out(no out put ) after about 10-12 loops, why is that?
Its because...........
well its hard to say by looking at the code you DID NOT POST. 
Or links to the sensors... and links to the default sketches.
Sorry I tried to post the code. but the forum says it has too many chars.
Ok, attached Re the ph , coductivity and combined code.
sensor_ph.ino (3.38 KB)
sensor_ph.ino (3.38 KB)
sensors_ph_conduct.ino (8.95 KB)
sensor_conduct.ino (5.69 KB)
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.htmlWelcome to the forum.
Please add your code as a attachment.
Thanks.. Tom.. 
Just checked sensors_ph_conduct.ino and found two oddities where comments and code contradict.
Line 69:
if (isdigit(sensorstring[0]) == false) { //if the first character in the string is a digit
Line 84:
if (computerdata[0] == 'c' || computerdata[0] == 'r')time_ = 900; //if a command has been sent to calibrate or take a reading we wait 1800ms so that the circuit has time to take the reading.
Other than that no obvious issues.
If you can't post all code in one message, just create a second one.