Heat pulsers are an item that we do not advertise because we only recommend them for use with the RTP or TST Heat & Temp units, and even then we advise you to be very cautious. If used improperly they are a fire hazard. You can build one on your own based on the instructions in the TST Heat and Temp curriculum, or you can buy an assembled one from us (order code HP-BTD). Both of these require the additional purchase of an immersion heater (usually found in the kitchen gadget section of your super market). Basically, the heat pulser works as a relay that is controlled by the interface. When you know how long the heat pulser turns on the immersion heater and the power output of the immersion heater in Watts, you can calculate the amount of heat added to the system.

If you are using the Heat Pulser with LabPro, you will need to be using Logger Pro 2.1 or newer. Earlier versions of Logger Pro will not work as explained below:

If you have the new Heat Pulser (HP-BTD) it ships with a CBL-RJ11 adapter and can be used with either LabPro or ULI. Note these cost a little more than the old HP.

If you have a old one (HP) it can be modified by adding a resistor (see below) and then combined with a CBL-RJ11 adapter. It will not work properly without the resistor (it will come on at LabPro startup). After modification, it can be used with either LabPro or ULI.

Modifying old Heat Pulsers:

You can use old heat pulsers with the CBL-RJ11 adapters added, but it is best to modify them by adding one resistor. The reason for the resistor is that if you do not have the resistor, every time you power up the LabPro, the heat pulser will come on briefly. This could cause the heat pulser to burn out, if it is plugged in and not in water.

The resistor is soldered on to the back (side facing you when you take the metal cover off the Heat Pulser. Take off the cover. Hold the heat pulser so that you can read the words Vernier Software. You will see some barely readable numbers at the top of the circuit board. Just below that and slightly left of it, you will find three solder connection points. The left most one is the ground plane. The resistor is soldered between the outer two of these three connections. We just tack it on with short leads and leave it close to the circuit board. The value of the resistor is 4.7k ohms.

We will be happy to add this resistor to your heat pulsers if you send them to us. If you prefer, you can do it yourself. If you do it yourself, do one and then plug it in and start up the LabPro. The thing to watch for is: does the red LED on the heat pulser flash during the startup sequence (sound from LabPro). If it does not, you have done it right. Also, you will want to check to make sure the heat pulser still works. If you would like us to perform the modification, contact our technical support staff to get a Return Merchandise Authorization.

Will the Heat Pulser work with LabQuest, LabQuest 2, LabQuest Mini, or LabQuest Stream?