Recommendation for Hall Effect Sensor

I am working on a precision position project and I am looking for advice regarding the selection of a Hall Effect Sensor. The sensor will be placed anywhere from 0.5 to 1 cm away from a magnet with a north and a south pole. When the sensor is moved over either pole I need it to send a signal to the Arduino Mega 2560 for processing prior to sending a signal to the actuator. I plan to power the sensor from the 5V supply of the board. I am pretty new to sensors and circuits.

What I am looking for:
Small and Compact
Sensing from 0.5 to 1 cm away
Sensing from 0 to 10,000 Gauss
Linear
Bipolar

Questions:

-Is there any advantage of digital vs. analog sensors? I think I will go with digital because I care about north or south poles, and a magnitude of 0.

-I found a few sensor for precision measurement but they were expensive (over 200 USD). Is it possible to use a more affordable sensor since it will be positioned so close the magnet it needs to read?

Some I have considered so far:

Expensive:
-Honeywell SPS-L075-HALS

-Honeywell SPS-L225-HALS

Affordable:
-Honeywell SS360NT

The analog hall sensors can also sense North and South.
An analog sensor is easier to start with, you don't have to communicate with the sensor.

For accurate temperatures (DS18B20) or baromic pressure (BMP085) I would advice a digital sensor. It is far more accurate. But to only detect something, analog is easier.

Some hall 'sensors' are hall switches. They switch the output at a certain level.
These are switches:

If you want to measure the level and also North and South, those are often ratiometric or linear.
They are 4 dollars for 10 of them on Ebay.
You have to read the datasheets to see if they have the range you need.

played with a hall effect some time ago - Arduino Playground - Hall Effect -

I think I have decided on this sensor, I just want to confirm it will perform inline with my requirements. The range of the magnetic field I need to sense is -180 to +180. The range is -650 to +650 Gauss. At maximum the sensor may be exposed to 9000 Gauss.

  1. Is it correct that if exposed to a magnetic field greater than it's specified range that the sensor will become saturated rather than damaged? Will it become unsaturated instantly once exposed to a magnetic field within it's range again?

  2. According to the data sheet I should have no issue powering this from the Arduino 5V pin right?

  3. How do you know which orientation to use for your sensor? Trial and error?

  4. Any reason not to choose this sensor?

Honeywell SS49E: Safety and Productivity Solutions | Honeywell

Data Sheet: 404: Not Found

My link to Ebay put the SS49E on top.
I already noticed that your magnetic level is beyond its range, but if clipping is no problem, I think it can be used.

  1. Magnetic Range, typical -100 mT to 100 mT [-1000 G to 1000 G].
    This applies to all hall sensors: “Magnetic fields that exceed the linear range of these Hall-effect ICs neither damage nor destroy the device. However, magnetic fields beyond the usable range force the output into saturation (and non-linear operation) without harm to the HED.
    http://www.allegromicro.com/Design-Center/Technical-Documents/Hall-Effect-Sensor-IC-Publications/Non-Intrusive-Hall-Effect-Current-Sensing-Techniques-for-Power-Electronics.aspx
    Restoring from saturation for a semiconductor is very fast. I think you will have no problem with that. But keep ferro metals away from the sensor. Any ferro metal might get magnetised with a strong field and influence the sensor.

  2. The 5V pin to power it, is perfect.

  3. A possitive Gauss makes the voltage go up. Is ‘North’ pole a positive Gauss? I think so.

  4. No.