Humidity Measurement
To measure relative humidity connect the probe to the socket. Set the
function switch to the “HUMIDITY” position. The unit is ready for
humidity measurements in the range of 20 t 90% RH.
NOTE: Temperature equilibrium is one of the biggest problems
connected with relative humidity measurements. Even the slightest
temperature difference between the measurement point and the
sensing element causes an error in the measurement result.
M a i n t e n a n c e
Service
WARNING!
Repair and service of this instrument is to be performed by qualified
personnel only. Improper repair or service could result in physical
degradation of the meter. This could alter the protection from electrical
shock and personal injury this meter provides to the operator. Perform
only those maintenance tasks that you are qualified to do.
Cleaning
Periodically clean your meter’s case using a damp cloth. DO NOT use
abrasive, flammable liquids, cleaning solvents, or strong detergents as
they may damage the finish, impair safety, or affect the reliability of the
structural components.
Battery Replacement
When the battery voltage decreases below a certain limit “LOBAT”
appears in the upper left hand corner of the display. This indicates low
voltage and the battery should be replaced with a new one. To replace
the battery, remove the battery compartment cover on the back of
the instrument.
S p e c i f i c a t i o n s
Introduction
The DTH1 is a process control instrument for measurement of humidity
and temperature. The instrument consists of a handheld indicator and a
probe with connecting cabl e.
Features include
• Easy to read 3 1/2 digit LCD display
• Low battery indication
• Humidity range: 20 to 90% RH
• Temperature range: -30˚ to 200˚F
• Cable length: 6’-7”
• Compact size
• Removable test probe
• Resolution: 0.1% RH/0.1˚F
Operating Instructions
Measuring Principles
The humidity sensor operates according to the resistive principle. The
resistance varies according to the ambient humidity. The measurement
of the resistive humidity depends on the change in the resistance. The
conversion is done electronically by using the most up-to-date highly
integrated components.
The relationship between the actual absolute humidity and the
maximum absolute humidity possible at the same temperature is
called the relative humidity. The relative humidity depends on the
temperature. In practice, a change in humidity will be related with a
change in temperature. This means that you must pay attention to the
temperature when measuring the relative air humidity. The response
time is much shorter in moving air because the heat transfer between
gases and solid-state material is reduced.
Function Switch
The function switch is on the left side of the instrument. It has the
following positions:
Connecting Probe to Instrument
A socket (receptacle) is on the top right hand side of the instrument for
connecting the probe.
The connector should always be carefully inserted in place and secured
with the lock washer.
DTH1-MAN P. 1
Op erating Tem p era ture 41˚ to 113˚F (5˚ to 45˚C)
Measuring Range - Humidity 20 - 90% RH
- Tem p e ra t ur e - 30˚ to20 0 ˚ F
Re solut i on 0.1% RH & 0.1˚ F
System Accura cy (At 68˚F) ±3% RH and ±1% of full scale
Di splay 3 1/2 digit LCD, 0.5 inch numerals
Measuring Environment Air
Power Supply 9 volt batter
B a t t e ryDuratio n About 200 hours of continuos use
Dimensions - Probe 0- 13/16 x 7-5/16 inches
- Instrument 5- 29 / 32 (H) x 2-5/16 (W) x 1-0 (D) inches
Cable Le n gth 79 inches (coiled cord)
Weight - Probe 3.5 ounces
- Instrument 5.6 ounces
Humidity measurement
Temperature measurement
Instrument power off
