8" (203mm) Temperature & Humidity Chart Recorder

This product has been replaced by the TH8P3

The TH803 has the features to direct your attention to out-of-range condition with both audio/visual alarms and large digital display of current or min/max conditions. The remote probe gives the TH803 even greater flexibility.

  • Remote Probe
  • Digital Display
  • Audio/Visual Alarms
  • 8" Chart (203mm)
  • User selectable recording times and temperature ranges
Important Information

Charts are sold separately.

Dickson Expert Services

Our Dickson Data Division has specially trained representatives to address the needs of customers with large installations or unique demands. Please call 888-452-4626.

  • Alarm Type Audio/Visual on High/Low Limits
  • Ambient Operating RH Conditions 0-95% RH non-condensing
  • Ambient Operating Temperature Conditions 32 to 120F (0 to 50C)
  • Approvals CE
  • Battery Backup Four AA Batteries. Powers unit for up to 3 Days.
  • Battery Life (Avg) 76 Hours (Back-up Only)
  • Calibration Options N100, N300, N400
  • Channels CH1: Temperature, CH2: Humidity
  • Chart Rotation Speed 24 Hour, 7 Day or 31 Day
  • Dew Point Accuracy +/-3.6F from 30 to 95% RH (Calculated) (+/-2C from 30 to 95% RH (Calculated))
  • Dew Point Range 32 to 122F (0 to 50C)
  • Dimensions 3.1 x 9.2 x 9.2in
  • Display Dimensions Height 1.375
  • Display Dimensions Width 2.0
  • Display Resolution 0.1
  • Display Type LCD
  • Enclosure Rugged Black ABS Case, Polycarbonate Door, Aluminum Dial
  • Humidity Accuracy +/-3% RH from 60 to 95%; +/-2% RH from 0 to 60%
  • Humidity Range 0-95% RH non-condensing
  • IP Rating 20
  • Included Accessories AC Adapter, Red and Blue Pen, Four AA Batteries, Quick Start Guide and Probe. *Charts sold separately.
  • Keypad Functions Power On/Off, Pen Home, Alarm
  • Mounting Options Free Standing or Wall Mount (With Keyhole)
  • Power Cord 6 ft
  • Power Source 120 to 240 VAC, 12 VDC (INTL fittings available); AC Adapter
  • Power Status Indicator LED Indicator
  • Remote Probe Dimensions Houses thermistor and RH sensor in polycarbonate plastic; 1.5" x 0.5" (1.25cm x 4.5cm)
  • Remote Sensor Length 10 ft
  • Remote Sensor Type Digital Temperature Sensor
  • Response Time 5 Minutes to 63% of Full Scale
  • Temperature Accuracy +/-1.8F from 32 to 120F (+/-1C from 0 to 50C)
  • Temperature Range Help-20 to 120F (-20 to 50C); 0 to 185F; 32 to 120F (0 to 50C); 40 to 110F (5 to 40C)
  • Temperature Sensor Remote Probe
  • Unit Weight 9 lbs
  • Units/Pkg 1
  • Warranty 12-Month Limited
Why should I calibrate?

All instruments lose accuracy over time due to normal usage and the environmental conditions to which they are exposed.

How often should I calibrate?

For most applications, the recommended calibration interval is every twelve months.

N100 1-Point NIST Traceable Calibration $99.00 Add
N300 3-Point NIST Traceable Calibration $156.00 Add
N400 3-Point Ultima NIST A2LA Accredited Calibration $269.00 Add
What is NIST Calibration

NIST stands for the National Institute for Standards and Technology. This organization is responsible for maintaining the master for different measurements, such as the standard "foot", standard, "second", or standard "pound". NIST also maintains the standard for temperature, humidity and pressure.

NIST Traceable means that the measuring standard can be traced directly back to the master standard maintained by the NIST organization.

NIST-Traceable does not tell you the measurement accuracy of a metrologty service in any detail. Only metrology services that can document their ISO 17025 standard provided data on their best measurement uncertainty.



Probe Dust Filter

Probe Dust Filter - prolong the life of your instrument.
Add to Cart



Universal Plug Kit for AC Adapter

Set of Three International Power Plugs for AC Adapter
Add to Cart



AC Adapter

AC Adapter
Add to Cart
C415 8" (203mm) Chart 24-Hour, -20 to 120 F $45.00 Add
C417 8" (203mm) Chart 7-Day, -20 to 120 F $45.00 Add
C437 8" (203mm) Chart 7-Day, 0 to 200 F $45.00 Add
C458 8" (203mm) Chart 24-Hour, 0 to 200 or 0 to 185 PSI/F $45.00 Add
C472 8" (203mm) Chart 24-Hour, -20 to 50 C $45.00 Add
C473 8" (203mm) Chart 7-Day, -20 to 50 C $45.00 Add
C476 8" (203mm) Chart 24-Hour, 40 to 110 F $45.00 Add
C477 8" (203mm) Chart 7-Day, 40 to 110 F $45.00 Add
C478 8" (203mm) Chart 24-Hour, 5 to 40 C $45.00 Add
C479 8" (203mm) Chart 7-Day, 5 to 40 C $45.00 Add
C480 8" (203mm) Chart 31-Day, -20 to 120 F $45.00 Add
C481 8" (203mm) Chart 31-Day, 40 to 110 F $45.00 Add
C482 8" (203mm) Chart 31-Day, -20 to 50 C $45.00 Add
C483 8" (203mm) Chart 31-Day, 5 to 40 C $45.00 Add
P246 3 Red, 3 Blue Pens $49.00 Add
For more information on this product and other 8" Temperature & Humidity Chart Recorders products see the 8" Temperature & Humidity Chart Recorders page.

Why don't the readings of the temperature pen and display exactly match?

Untitled Document The cause of this could be because Hysteresis or wrong chart
  • Hysteresis is a naturally occurring mechanical discrepancy up to 2% of range
  • Check to see that the proper chart is installed

What do I do if the probe has been exposed to environments exceeding 95% RH for an extended period?

Untitled Document
  • Probe should be dried out under normal ambient conditions – time required varies on temperature, RH and air flow

Why is the alarm symbol flashing on the digital display?

Untitled Document
  • Alarm sounds audibly if out of range conditions occur, then indicator will flash until alarm key is pressed and alarm is reset (press alarm button)

What if there is no power to the unit?

Untitled Document
  • Check the the AC adapter

What if my chart does not have an Rh line?

  • If your chart does not have an Rh line it uses the same scale as the temperature.

How do I adjust the pens?

Pen adjust may be needed if the pen(s) and display do not match.  Before proceeding check your calibration date, the unit may be due for a recalibration, if so contact Dickson.

While the unit is on, press and hold both the Pen Home button and the On/Off button (making sure to press the Pen Home button first so the unit will not turn off). The led will blink rapidly between amber and green for about five seconds, the LED will then turn green, release the Pen Home and On/Off buttons. The led will flash amber and green for one second and the led will turn off.

One pen model: The red pen will move to the outer edge of the chart and is ready to be adjusted. Use the Adjust-Up and Adjust-Down buttons to move the pen to the maximum temperature line on the chart. Once the pen is set, the Pen Home button will move the pen to reaffirm the new pen position. Press the On/Off button to exit pen home adjust.

Two pen models: Both pens will move to the outer edge of the chart, and then the shorter red pen will move to the current position. Use the Adjust-Up and Adjust-Down buttons to move the pen to the maximum temperature line on the chart. Once the shorter red pen is set, the Pen Home button will move the shorter red pen to the outer edge of the chart and the longer blue pen will move to its current position. The Adjust-Up and Adjust-Down buttons will adjust the longer blue pen position. Once the pen is set, the Pen Home button will move the longer blue pen to the outer edge of the chart and the shorter red pen will move to its new position. Each time pen home is pressed the two pens will switch positions (moving the most recently adjusted position) until the On/Off button is pressed to exit pen adjust mode.

Note: Pressing the On/Off button will exit the adjustment and return the unit to normal operation. Each time the pen home or On/Off button is pressed, the adjustment currently in progress will be stored. The unit will take one minute to exit Pen Adjust Mode once the On/Off button is pressed.

How do I set the Alarm(s)?

1. Alarm on or off
2. Pen 1 alarm min
3. Pen 1 alarm max
(if it is a two pen unit the following states also exist)
4. Pen 2 alarm min
5. Pen 2 alarm max

To set the alarm, make sure unit is on and press and hold the Alarm button. The LED will blink red rapidly for about five seconds, and then the led will go solid green. Release the Alarm button and the led will turn red. At this point the display will show the following: ON with a delta symbol, or OFF without a delta

Pressing either the Adjust-Up or Adjust-Down buttons, located on the back of the unit next to the dip switch, will toggle the alarm on/off.

Pressing Pen Home will scroll to the next alarm option. The options are as follows:

In order to set pen alarm minimums and maximums, pressing the Adjust-Up will increase the alarm value, and pressing the Adjust-Down will decrease the alarm value. There is acceleration if the Adjust-Up button is held down. Repetitively pressing the pen home button will scroll through the five options until the alarm button is pressed to exit from alarm adjust. Each press of the Pen Home or Alarm button will store the new settings. The unit will take one minute to exit Alarm Set Mode once the Alarm button is pressed.

If the alarm is triggered, ALRN will show on the display, the led will show as solid red and the alarm will sound. Press the Alarm button to silence Audible Alarm.

What do the different colors on the LED Light mean?

Solid Green - AC Power with Battery Backup
Blinks Red - AC Power with Low Battery or No Battery

Blinks Green - Battery Only
Solid Red - Battery Only (Low Battery)

What if my instrument is not responding to a key press?

  • Try slower, firmer key presses.
  • Maybe the unit is locked up. If the chart recorder is locked up there will be no response to button presses, however, the unit may appear to be working, but the readings won't change and the chart will not rotate. To correct this, remove ac and battery power then re-power.

Why can't I get into calibration mode using the "on/off" and "adjust down" buttons?

  • Use the "on/off" and "adjust up" buttons if the "on/off" and "adjust down" buttons don't work.

Why is my LED flashing red?

Untitled Document
  • When the backup battery is low, the LED will flash red until the battery has been replaced.

Why is the LED not solid green when the unit is on?

The green LED flashes only occasionally to preserve battery life.

Why is the response time slower when the unit is powered by batteries only?

Response time is slower to preserve battery life.

Why won't the alarm work when the unit is set for Celsius?

Make sure the unit is in Fahrenheit when setting the alarm for the first time. Switch to Celsius and reset the alarm parameters.