Temperature related equipment
This page contains information about equipment I have build for various computers which are related to temperature.
Rat heart thermometer
This thermometer uses a small thermistor probe which is used to measure
the temperature of a rat heart on a perfusion system. The temperature
is
displayed on a LCD display. I have build several of these units. Below
is a photo of one of the
units:
This thermometer has become a vital tool for several perfusion
laboratories
in South Africa. Temperature plays a very important role in the
performance
of the rat heart, or any other heart, on the perfusion system. In the
past
several experiments failed because of an error in the temperature.
Using
this thermometer the perfusionist is able to immediate diagnose a
temperature
error and make corrections to the water bath's temperature (which is
not
the same as the heart's temperature).
Below is a more recent version of the thermometers:
Temperature alarm
This temperature alarm is used to monitor the temperature of freezers
and refrigerators used in laboratories for storing chemicals and
samples. If the temperature rises above a user settable value, an alarm
output is triggered. I have build two versions of these temperature
alarms. The standard range unit has a temperature range from -40
degrees
centigrade to +50 degrees centigrade. The ultra low range has a
temperature range of -100 degrees centigrade to 0 degrees centigrade.
The alarm output is in the form of a normally closed relay, which may
be connected to an alarm circuit. The alarm has a time delay function.
This time delay function is needed since if a freezer is opened to
insert or remove samples, the temperature will rise. Only if the
temperature is above the setpoint for about 60 minutes on the current
units, the relay will open to indicate the alarm condition. During the
time delay the display flashes between the current temperature and the
time which has so far elapsed since the temperature limit has been
exceeded.
Server room temperature alarm
This temperature alarm has been designed to monitor the temperature of
a computer server room. If the temperature goes above a certain
threshold, the alarm is triggered. The alarm has a remote siren and
strobe which is located outside the server room. There is also a remote
mute button to silence the siren. Below is a picture of the main
controller unit. This unit contains the main electronics and power
supply. Since this temperature alarm is used in conjunction with a
network server, it does not have any battery backup supply since it
gets power from the UPS which is used to power the server.
The temperature is displayed at the left with the setpoint adjust
buttons just to the right of the display. The silver button at the
bottom is used to mute th siren. The ALARM indicator will flash as long
as there is an overtemperature condition. The main controller unit is
mounted inside the server room. Below is a photo of the remote
strobe/siren unit. This unit is mounted outside the server room, the
distance is not that critical.
Below is a photo of the remote MUTE button. Pressing this button only
mutes the siren, but the strobe will keep flashing as long as there is
an overtemperature condition.
The main controller also has a relay output which may be connected to an external alarm system or even an autodialer.
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