MicroTim XB User Manual

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MicroTim XB™

Precision Digital Barometric Altimeter / Barometer / VSI

Document Revision 1.0

Firmware Version 3.0

User Manual

Table of Contents

Table of Contents ..................................................................2

1 General Operation..........................................................5

1.1 Altitude Display Modes.........................................5

1.2 Units ......................................................................5

1.3 Restoring Factory Default Settings........................5

2 Display Mode Examples................................................6

2.1 ASL Display Example...........................................6

2.2 AGL Display Example ..........................................6

3 Keypad Function Details ...............................................7

4 Setting the Barometric Pressure ....................................8

5 Field-Elevation Mode....................................................8

6 Barometer Mode............................................................9

6.1 Activating Barometer Mode ..................................9

6.2 Calibrating the Barometer .....................................9

6.2.1 Calibrating Barometer Mode by Known Elevation 9

6.2.2 Calibrating by Known Barometric Pressure..9

6.3 Using the Barometer..............................................9

6.3.1 Barometer Units...........................................10

6.4 Exiting Barometer Mode .....................................10

7 VSI Mode ....................................................................10

7.1 Activating VSI Mode ..........................................10

7.2 Using VSI ............................................................10

7.2.1 VSI Units .....................................................11

7.2.2 VSI Deadband .............................................11

7.3 Exiting VSI Mode................................................11

8 Vertical Accumulator Mode ........................................11

8.1 Activating Accumulator Mode ............................11

8.2 Using the Vertical Accumulator..........................11

8.2.1 Zeroing the Accumulator.............................12

8.2.2 Accumulator Units.......................................12

8.2.3 Accumulator Deadband ...............................12

8.2.4 Accumulator Sampling Rate........................12

8.3 Exiting Accumulator Mode .................................12

9 MicroTim XB Messages..............................................13

10 Changing the Battery...............................................13

Appendix A – Frequently Asked Questions........................14

WARNING!

- DO NOT OVER-TIGHTEN THE SCREWS when changing the battery. Warranty does not

cover stripped screw holes.

- The battery cover is recessed to clear the battery and only fits correctly one way. Observe the recessed battery cover when replacing the battery.

Serial Number_____________________ Firmware Revision Number__________ Checked: _________________________

MicroTim XB is a precise, durable, low-power digital barometric altimeter.

Here are some of the major features of the MicroTim XB altimeter:

• Lightweight and portable.

• Ultra Low power consumption. Runs for many months on a single replaceable AAA penlight

battery.

• Battery monitoring. Typically several days warning of a low battery.

• Displays in units of meters/kPa or feet/inHg or feet/mbar.

• Barometric pressure adjustable.

• Factory calibrated.

• Durable. Moisture and vibration resistant.

• Can function as a high precision barometer.

• Can function as a VSI (Vertical Speed Indicator)

• Can function as a Vertical Accumulator (total vertical distance traversed).

1 General Operation

MicroTim XB is turned on by holding the key until ‘boot’ appears on the display and release the key. All of the configuration instructions in this manual assume MicroTim XB is already turned on and running.

The sealevel altitude (ASL) is displayed when no key activity has occurred in the past 5 seconds.

The barometric pressure setting corrects these altitude readings for weather changes and is set by single

press/releases of the altitude keys . The default barometer setting is 2992 (29.92 inHg).

1.1 Altitude Display Modes

MicroTim XB can be configured to display:

• ASL (default). Unsigned number. Arrow indicates negative readings (below sealevel).

• AGL (Altitude above Ground Level). Sign (+/-) is displayed to show altitude above (+) or below (-) the

location MicroTim XB was last zeroed at.

• Both AGL/ASL alternately every 2 seconds.

To change the display mode, hold the display key for 5 seconds then release. MicroTim XB will then flash the selected display mode (ASL, AGL, BOTH) for 5 seconds.

1.2 Units

MicroTim XB displays altitude in feet and barometric pressure in inches of mercury by default. Three sets of units are available:

1) Altitude in feet, barometric pressure in inches of mercury (default).

2) Altitude in meters, barometric pressure in kPa.

3) Altitude in feet, barometric pressure in millibars.

To change units, hold the units key for 5 seconds then release. MicroTim XB will then flash the selected unit pairing (FEET, METR, FTMB) for 5 seconds.

After 20 minutes of inactivity (no key activity or significant altitude changes) MicroTim XB powers down. To

restore normal operation, press and hold the key until ‘boot’ appears on the display.

1.3 Restoring Factory Default Settings

By default, MicroTim XB is in altimeter mode, displaying ASL in feet and barometric pressure in inches of mercury.

Holding down the reset key for 5 seconds then releasing will restore these factory default settings.

During a system reset, MicroTim XB will display:

1) The unique electronic serial number, ‘sern’ followed by the serial number.

2) The firmware version, ‘frn’ followed by the firmware version.

3) A screen test, cycling from ‘0000’ to ‘9999’.

4) The defaulted barometric pressure, 2992.

then MicroTim XB resumes normal operation with the default settings.

2 Display Mode Examples

2.1 ASL Display Example

This is the altitude above mean sea level, also referred to as MSL.

The ASL altitude appears as an UNSIGNED number. In the case of being BELOW sea level, an ARROW will appear in the upper left corner of the display to indicate an altitude below sealevel.

Examples of ASL readings:

ASL

Reading

2368

←

0421

MicroTim XB is 2368 units ABOVE mean sea level.

MicroTim XB is 421 units BELOW mean sea level.

Meaning

2.2 AGL Display Example

This is the altitude above a user-selected ground level.

The AGL altitude always appears with a ‘+’ or ‘-‘ sign. This is what distinguishes AGL from the ASL altitude (ASL altitude uses an arrow to indicate values below sealevel). Zero the AGL at any altitude with a quick

press/release of the zero key .

Examples of AGL readings:

AGL

Reading

+1368 MicroTim XB is 1368 units ABOVE

ground level.

-0652 MicroTim XB is 652 units BELOW ground level.

Meaning

3 Keypad Function Details

There are three keys on MicroTim XB, not six.

Each key has 2 functions:

1. A primary function (upper text) activated by quick press/release.

2. A secondary function (lower text) activated by holding the key down for 5 seconds then releasing.

4 Setting the Barometric Pressure

MicroTim XB contains a barometric pressure setting which allows the user to enter the current local barometric pressure to correct the altitude readings for weather changes.

To VIEW the current barometer setting, press either of the alt keys once. MicroTim XB will display the barometer setting for 5 seconds.

To CHANGE the barometer setting, repeatedly press/release the alt keys until the desired barometer setting is achieved.

When viewing altitude in ‘metr’ (meters/kPa) mode, the barometric pressure reads in units of kPa and 101.32 kPa will display as 10132.

When viewing in ‘ftmb’ mode, the barometric pressure reads in units of mbar (millibars). Note that since the decimal point is not shown, mbar units will display the same as kPa units. For example, 1013.2 mbar will read as ‘10132’.

When viewing in ‘feet’ mode, the barometric pressure displays in units of inHg, and 29.92 inHg will display as

2992.

5 Field-Elevation Mode

Many users will not have access to the current barometric pressure for their area, but will know their current starting elevation. Trial and error finding the correct barometric pressure setting to produce this known starting elevation can be tedious. To ignore barometric pressure altogether, and dial in a known starting elevation, place MicroTim XB in field-elevation mode.

To toggle MicroTim XB between field-elevation (fld) and barometric pressure (bp) modes, do a quick press/release each of the keys in the following sequence:

That is: up/down/up/down/zero, up/down/up/down/zero.

Then ‘fld’ or ‘bp’ will appear on the screen, verifying that the mode has been successfully changed. Repeat this sequence until desired mode appears.

Note: To prevent accidental activation of the bp/fld mode selection, MicroTim XB ignores the sequence if more than 2 seconds elapses between any of the keypresses in the sequence.

Once field-elevation mode is achieved, pressing the alt keys now immediately displays the newly adjusted altitude. In this mode MicroTim XB does not display the barometric pressure at all but still adjusts the altitude by

0.01 inHg (0.339 mbar or about 9.3 feet) with each or keypress.

Note: Upon reset, MicroTim XB defaults to ‘bp’ mode.

6 Barometer Mode

MicroTim XB is primarily for altitude indication. However, it can also be configured to act as a high-precision barometer when it remains at a constant elevation. Barometer mode is activated by executing a special system reset.

6.1 Activating Barometer Mode

To activate barometer mode:

1) Begin a system reset by holding down the key for 5 seconds then releasing the key. The system reset

will begin when the key is released. During the reset MicroTim XB will show the serial number ‘sern’ and firmware revision number ‘frn’ followed by a screen test starting with ‘0000’ and ending with ‘9999’.

2) At any time during the screen test (before ‘9999’ appears) press and hold the key. If this key is being

HELD DOWN as the reset cycle completes (i.e. showing 9999 on the screen) then MicroTim XB will enter barometer mode. Do not release the key until ‘baro’ appears on the display. MicroTim XB is now in

barometer-mode and you may release the key.

6.2 Calibrating the Barometer

When set to barometer mode, MicroTim XB assumes a barometric pressure of 29.92 inches of mercury. This reading needs to be calibrated to your elevation. Once it has been calibrated, the barometer will read correctly always, unless MicroTim XB is moved to another elevation.

6.2.1 Calibrating Barometer Mode by Known Elevation

If you know the elevation MicroTim XB is at, you can calibrate the barometer by entering this elevation. Press the

keys until the correct elevation appears on the screen. The elevation will increment in 9.3 foot steps, equivalent to 0.01 inHg at sealevel. Select the elevation closest to your true elevation. After no keys have been pressed for 5 seconds, MicroTim XB will stop displaying the reference elevation and show the correct barometric pressure.

6.2.2 Calibrating by Known Barometric Pressure

Note that alternatively you may simply know the current barometric pressure in your area and use the keys to force MicroTim XB to this value. From then on, MicroTim XB will display the correct barometric pressure.

6.3 Using the Barometer

In barometer mode, MicroTim XB displays the barometric pressure constantly. MicroTim XB updates the reading once per minute. After an idle period of approximately 30 minutes, MicroTim XB will power down. The barometer

will resume operation any time afterward by turning the unit back on (holding the key until ‘boot’ appears on the display).

6.3.1 Barometer Units

The three unit combinations available in altimeter mode are also available in barometer mode. The default is inches of mercury for pressure and feet for reference elevation (inHg/feet). You may toggle through metric (kPa/meters)

and mixed (mbar/feet) by holding the key for 5 seconds then releasing.

6.4 Exiting Barometer Mode

Normal altimeter operation is restored by executing a NORMAL system reset (by initiating a reset and NOT touching any keys until it is complete). See section 1.3, Restoring Factory Default Settings.

7 VSI Mode

MicroTim XB is primarily for altitude indication. However, it can also be configured to act as a VSI (Vertical Speed Indicator). Like barometer-mode, vsi-mode is activated by executing a special system reset.

7.1 Activating VSI Mode

To activate VSI mode:

3) Begin a system reset by holding down the key for 5 seconds then releasing the key. The system reset

4) At any time during the screen test (before ‘9999’ appears) press and hold the key. If this key is being

HELD DOWN as the reset cycle completes (i.e. showing 9999 on the screen) then MicroTim XB will enter vsi-mode. Do not release the key until ‘VSI’ appears on the display. MicroTim XB is now in vsi-mode and

you may release the key.

7.2 Using VSI

In vsi-mode, MicroTim XB displays your vertical speed in units per minute (feet per minute by default). A ‘+’ sign indicates climb, and a '-' sign indicates sink.

Some examples of VSI readings are:

VSI

Meaning

Reading

+ 0160 MicroTim XB is CLIMBING at an

average rate of 160 units per minute.

- 1150

where ‘units’ are feet by default, but may be set to meters by changing the units (see section 7.2.1).

7.2.1 VSI Units

The unit selections available in altimeter mode are also available in vsi mode. The default is feet per minute. You

may toggle to metric (meters per minute) by holding the key for 5 seconds then releasing.

7.2.2 VSI Deadband

MicroTim XB will display as zero any climb/sink rate less than 30 feet per minute.

7.3 Exiting VSI Mode

Normal altimeter operation is restored by executing a NORMAL system reset (by initiating a reset and NOT touching any keys until it is complete. See section 1.3, Restoring Factory Default Settings.

MicroTim XB is DESCENDING at an average rate of 1150 units per minute.

8 Vertical Accumulator Mode

MicroTim XB is primarily for altitude indication. However, it can also be configured to act as a vertical accumulator. This logs the total vertical distances traversed by the unit since last zeroed. Like barometer and vsi modes, accumulator mode is activated by executing a special system reset.

8.1 Activating Accumulator Mode

To activate accumulator-mode:

5) Begin a system reset by holding down the key for 5 seconds then releasing the key. The system reset

6) At any time during the screen test (before ‘9999’ appears) press and hold the key. If this key is being

HELD DOWN as the reset cycle completes (i.e. showing 9999 on the screen) then MicroTim XB will enter accumulator-mode. Do not release the key until ‘ACC’ appears on the display. MicroTim XB is now in

accumulator-mode and you may release the key.

8.2 Using the Vertical Accumulator

In accumulator-mode, MicroTim XB displays 3 distances in a cyclic fashion, all in TENS of units (feet or meters):

1) Vertical distance CLIMBED (+).

2) Vertical distance DESCENDED (-).

3) The sum of 1) and 2), total vertical distance (no sign).

Some examples of accumulator readings are:

Accumulator

Meaning

Reading

+ 0300 MicroTim XB has CLIMBED 3,000

units since last zeroing.

- 1288

MicroTim XB has DESCENDED 12,880 units since last zeroing.

1588 Total vertical units traveled are 15,880

units (i.e. 3,000 + 12,880 = 15,880).

8.2.1 Zeroing the Accumulator

Pressing the key sets all 3 accumulator quantities to zero.

8.2.2 Accumulator Units

The unit selections available in altimeter mode are also available in accumulator-mode. The default is feet. You

may toggle to metric (meters) by holding the key for 5 seconds then releasing.

8.2.3 Accumulator Deadband

After each reading, MicroTim XB will ignore any changes in altitude of 2 feet or less.

8.2.4 Accumulator Sampling Rate

MicroTim XB accommodates two sampling rates. ‘FAST’ sampling rate (default) and a slower sampling rate for slower vertical movement ‘SLO’, where the accumulator deadband may be causing slow climbs/descents to be

ignored by MicroTim XB. To toggle between slow/fast sampling rates, hold for 5 seconds and release. ‘FAST’ or ‘SLO’ will display, showing the new rate.

Be aware that in slow mode, brief changes in altitude can be missed. For example a 10 foot vertical dip lasting 10 seconds may not register on MicroTim XB. Fast mode (the default) has a better chance of detecting this 20 feet in vertical distance traveled.

8.3 Exiting Accumulator Mode

Normal altimeter operation is restored by executing a NORMAL system reset (by initiating a reset and NOT touching any keys until it is complete). See section 1.3, Restoring Factory Default Settings.

9 MicroTim XB Messages

MicroTim XB can display the following messages.

MESSAGE:

rger Range Error. Out of the calibrated range of 2000

ader Internal hardware failure. Unit requires service.

feet Units have just been changed to feet/inHg

metr Units have just been changed to meters/kPa

ftmb Units have just been changed to feet/mbar

bp MicroTim XB has just been switched to

fld MicroTim XB has just been switched to field-

frn Firmware revision number (i.e. software version)

sern Electronic serial number follows this message.

agl MicroTim XB has just been configured to display

asl MicroTim XB has just been configured to display

both MicroTim XB has just been configured to display

baro MicroTim XB is now in barometer mode.

VSI MicroTim XB is now in VSI mode.

ACC MicroTim XB is now in vertical accumulator

FAST Accumulator is now in FAST sampling mode.

EXPLANATION:

to +19999 feet.

barometric-pressure mode (as opposed to field-

elevation mode).

elevation mode.

follows. Upon reset, MicroTim XB displays ‘frn’ then firmware revision number.

Upon reset, MicroTim XB displays ‘sern’ then the unique electronic serial number of this unit.

only AGL altitude.

only ASL altitude.

both AGL and ASL altitudes.

mode.

SLOW Accumulator is now in SLOW sampling mode.

batt Low Battery. Install a fresh high-grade battery.

10 Changing the Battery

The MicroTim XB digital is a low power device which will operate for months on a single high-end (for example ‘Energizer E2’) ‘AAA’ size penlight battery. A high quality alkaline battery is obviously preferable in terms of battery life. Do not use rechargeable batteries, as these types of batteries self-discharge relatively quickly.

To change the battery:

1) Place the unit on a soft cloth or hold the unit to prevent scratching the faceplate while changing the

battery.

2) Remove the 2 Philips screws by turning them counter clockwise.

3) Gently remove battery by pulling the ribbon upward.

4) Re-position the ribbon under a fresh battery, observing the correct polarity.

5) Turn unit back on by holding the key until ‘boot’ appears on the display.

6) Replace cover, and the two screws. DO NOT OVER TIGHTEN THE SCREWS. These screws will

not vibrate loose, and gentle tightening is all that is required. MicroTim XB is not warranted for stripped holes. Also, the lid is recessed to clear the battery and fits correctly only one way. Observe the recess in the cover.

Appendix A – Frequently Asked Questions

Question: When in ‘ftmb’ or ‘metr’ modes, I cannot reach the exact number I am trying for. Why not?

Answer: MicroTim XB is changing the barometric pressure internally by 0.01 inHg (9.3 feet) then converting to mbar or kPa. Pick the number closest to the setting you are trying for.

Question: This is a barometric altimeter. How does the sensor access the local pressure?

Answer: MicroTim XB has an unsealed rear cover which allows the internals to equalize with external air pressure. In addition, a small hole in the cover is present to ensure equalization. The rear cover and this small hole should

never be sealed or the accuracy of the unit will be severely affected.

Question: What if I have a problem I cannot seem to solve?

Answer: Go to http://www.microtim.com, or email support@microtim.com and we will answer any questions you have.

Question: What does the warranty cover?

Answer: MicroTim XB is warranted for a period of one year from date of purchase against defects in workmanship. The following items are NOT covered:

1. Bleeding LCD displays (black spots). This is a direct effect of being overly shocked (dropping from

a significant distance onto concrete, for example) or being subjected to excessive cold/hot temperatures.

2. Being subjected to temperatures out of the specification. An internal temperature sensor logs the

maximum/minimum temperatures ever encountered by the unit. The -20C to +85C range must be maintained.

3. Stripped holes due to over-tightening screws. Gently tighten until snug. They will not vibrate loose.

4. Cosmetic damage like scratching the cover, or using sharp objects or fingernails to push the 3

buttons. Faceplates can, however be replaced for a charge. Email repairs@microtim.com for details.

MicroTim XB User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual