UEi Test Instruments DTH31 - Manual (Page 4)

MIN/MAX Function
1. Press “ “ button until “MIN” appears in display (Fig 6). Display
is now showing minimum humidity and temperature reading.
2. Press “ “ button again until “MAX”appears in display (Fig 7).
Display is now showing maximum recorded humidity and
temperature readings.
3. Press “ “ button until “MIN” or “MAX” disappear from display
to return to current readings.
4. Press “ “ button for more than 2 seconds to clear current
reading from memory.
*
NOTE: While checking MIN/MAX value for T2, ∆T, ∆DP, don’t replace the
probe or the error code will display. The error code will also appear if the
probe is not installed when checking MIN/MAX values.
∆T/DP and ∆DP/WB
T1 T2
∆T - is calculated by subtracting the T2 (Ex. temp.) from T1 (Air temp.).
∆DP - is calculated by subtracting the DP (dew point) from T2 (Ex. temp.).
1. Press “ “ button until ∆T appears in display (Fig 8).
2. Press “ “ button until ∆DP appears in display (Fig 9).
Low Battery
A battery symbol will display in the upper right corner when the battery
is low. Inaccurate readings will result from low batteries (Fig 10).
1. Open the battery cover on the back of instrument.
2. Remove the expired batteries.
3. Insert two new AAA V batteries.
Troubleshooting
Note: Dry bulb temperature is air (internal) temperature. Dew point
and wet bulb are calculated from internal temperature and humidity.
Specifications
Standard & Optional Accessories
Optional
External temperature probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ATT31
DTH31-MAN P. 3
(Fig 6) (Fig 7)
(Fig 8) (Fig 9)
If I See This I Should Check
Malfunction
Make sure the time of pressing “ “ - ON/OFF key is more
than 0.1 sec.
Check that the batteries are inserted correctly.
Replace batteries if needed
Confirm battery indicator is displayed before display
disappears. If yes, replace with new battery
Check if sleep mode is active. If yes, press “ + HOLD”
button to disable auto power off function
Circuit error in RH measurement - Return instrument to UEi
for repair (see warranty)
Circuit error measuring internal temperature - Return
instrument to UEi for repair (see warranty)
Circuit error in self calibration channel - Return instrument to
UEi for repair (see warranty)
Internal temperature is out of range
External temperature is out of range
No display
Er 1
Er 2
Er 3
Er 4
Er 5
(Fig 10)
Temperature
Temperature range -4 to 122˚F (-20 to +50˚C)
RH% 0 to 100% RH
Wet bulb -69 to 122˚F (-21.6 to 49.9˚C)
Dew point -90.4 to 122˚F (-68 to 49.9˚C)
External temperature -4 to 158˚F (-20 to 70˚C)
Accuracy
RH% ±3% at 77˚F (25˚C)
Temperature ±1˚F (0.6˚C)
General
Response time 60 seconds typical
Size 1” (H) x 1 7/8” (W) x 7” (L)
Cable length 45 5/8”
Probe (w/handle) 7 7/8”
Battery 2 x 1.5V AAA batteries